University of Rochester C. E. K. Mees Observatory - Astro Pas ...

University of RochesterC. E. K. Mees ObservatoryRochester, NY 14727-01 71This year's "Report of the C.E.K. Mees Observatory"covers activities of the faculty, staff and studentsat the University of Rochester, as well as of the Mees Associates,during the period 1 October 1993 to 30 September1994. The Astronomy faculty at the University ofRochester includes Kaiyou Chen, W. J. Forrest, H. L.Helfer (Emeritus and Faculty Associate), J. L. Pipher,M. P. Savedoff (Emeritus), S. L. Sharpless (Emeritus),J. H. Thomas, H. M. Van Horn, M. Wardle and D. M.Watson. H. W. Fulbright, Emeritus Professor of Physics,remains involved in the Observatory.D. Meisel (SUNY Geneseo) and Z. Ninkov (RochesterInstitute of Technology) are Associates of the C. E. K.Mees Observatory. Meisel acts as Associate Director ofthe Observatory. Forrest was appointed Director of theC.E.K. Mees Observatory 1 June 1994.Pipher completed her term as a member of theBoard of Editors of the PASP in early 1994. She is in thethird year of a three year term on NASA's IR/SubMM/Radio Management and Operations Working Group.Pipher is in her second year of a three year term as memberof the AAS council, and is a member of the SpaceStudies Board (SSB) of the National Research Council(NRC). As part of her duties on the SSB, she is a memberof the Joint Committee on Technology for Space Scienceand Aeronautical Engineering, which has embarked ona study requested by Congress, "The Future of SpaceScience". Pipher served on a subcommmittee of theNRC Committee for Astronomy and Astrophysics, theso-called "Panel on Ground-based Optical and InfraredAstronomy". The panel, chaired by R. McCray, JILA,was charged with recommending a strategy for NSF supportof ground-based optical and infrared astronomy inthe Gemini era. She also served on the Gemini DirectorSearch Committee, chaired by J. Huchra (SAO). Amongher proposal review activities, she served on the NASA2MASS Survey review committee, and the NSF SDSS reviewcommittee. Pipher is also a member of the NRAOVisiting Committee for the next three years. She gavetwo Shapley lectures at St. Lawrence University andparticipated in an astronomy class.Watson continues to serve on the NSF Graduate Fellowshipreview panel, and served on the astronomy reviewpanel for the NSF Young Investigator Program.Forrest, Pipher and Watson are members of theinstrument teams for the NASA Space Infrared TelescopeFacility (SIRTF), and are responsible for a substantialamount of the detector array development forthese experiments. Forrest and Pipher are members ofthe SIRTF Infrared Array Camera (IRAC) team, andForrest and Watson belong to the SIRTF Infrared Spectrograph(IRS) consortium.Kaiyou Chen completed one year as visiting assistantprofessor and returned to Los Alamos National Laboratory.During the summer of 1994, Chen presentedinvited lectures at several institutes in China, includingNanjing University, the Institute of High Energy Physics,and the China Center for Advanced Science and Technology.Thomas was on academic leave during 1993-94 withthe support of a Guggenheim Fellowship. He spentone month at LAEFF in Madrid working with B. Montesinos,one month at the Max-Planck-Institute for Astrophysicsin Garching (Munich), and also visited theObservatoire du Pic du Midi and the Observatoire deParis (Meudon). He gave an invited talk on L'The Causeof the Evershed Effect in Sunspots: Flows or Waves'' atthe NATO ARW on Solar Surface Magnetism in Soesterberg,The Netherlands in November 1993, and an invitedtalk on "Siphon Flows in Photospheric Magnetic FluxTubes" at the meeting on Current Trends in Solar andAstrophysical Magnetohydrodynamics in Boulder, Coloradoin July 1994.In June 1994, Thomas was elected vice-chair andchair-elect of the Solar Physics Division of the AAS. Hewill serve as vice-chair in 1994-95, as chair in 1995-97,and again as vice-chair in 1997-98. Thomas continues toserve as an associate editor of The Astrophysacal Journal.Van Horn took a two-year leave of absence from theUniversity of Rochester, beginning in July 1993, to serveas Director of the Division of Astronomical Sciences atthe National Science Foundation, in Washington, DC.In an effort to improve communication between NSFand the US astronomical community, he has begun regularcontributions to the AAS Newsletter; to date hehas contributed six columns. Van Horn also was electedto chair the Publications Board of the American kstronomicalSociety (AAS), assuming this position followingthe June, 1993 meeting of the AAS. He served in thiscapacity for one year, resigning in May 1994 to concentratehis full attention at NSF. He remains a member ofthe AAS Publications Board, however. He also servedthe fourth year of a five-year term as a member of theAAS Advisory Committee for the Annie Jump CannonAward for young women in astronomy. On 22 March1994, he participated in a program at Wesley College inDover, DE, at which Dr. Barbara Welther of Harvardwas awarded the Annie Jump Cannon Medal by thatinstitution. In addition, during the 1993-94 academicyear he served as Chair of the Astronomy Section of theAmerican Association for the Advancement of Science(AAAS). He has also agreed to serve as a member of theO American Astronomical SocietyProvided by the NASA Astrophysics Data System

UNIVERSITY OF ROCHESTER 561International Scientific Committee for the InternationalConference on the Physacs of Strongly Coupled Plasmas,to be held in Binz/Rugen, Germany, in September 1995.Van Horn presented several invited lectures in 1993-94. He spoke on "Equations of State in Stellar Structureand Evolution" at IAU Colloquium 147, in St.Malo,France, on 14 June 1993 (Van Horn 1994), on "ThePhysics of White Dwarfs" at the 9th APS Topical Conferenceon Atomic Processes in Plasmas, in San Antonio,TX, on 20 September 1993, and on "Global Oscillationsof Neutron Stars as Potential Probes of MicroscopicPhysics at Ultra-High Densities" at the International OjiSeminar, in Tomakomai, Japan, on 28 June 1994 (VanHorn ei al. 1994).Thomas and Van Horn completed the third year oftheir NASA Theory Grant, on "The Seismology of Rotating,Magnetic Stars," which supports the research oftheir joint astrophysics theory group. The research programof this group includes investigations of oscillationsand other physical properties of the Sun, giant planets,"brown dwarfs," white dwarfs, accretion and "excretion"disks, neutron stars, and astrophysical jets.Wardle joined the faculty effective July 1993, but remainedat Northwestern University on leave during thefall semester of 1993. He moved to Rochester in January1994. While at Northwestern he continued collaborationswith F. Yusef-Zadeh and A. Konigl (U. Chicago).In addition to their collaborative research, Wardle andYusef-Zadeh are co-writing a book about the GalacticCenter for Cambridge University Press.Helfer officially retired as of 1 July 1992 but remainsactive in the Department. He served as Rochester's representativeon the Board of Directors of the New YorkAstronomical Corporation.Ninkov continues studies into the development ofcharge injection devices under the auspacies of a NationalScience Foundation Industry University Cc-operativeResearch Center (IUCRC) and a New York StateCenter for Advanced Technology (CAT) grant whichsupports the activities of faculty participants in the Instituteof Optics, Department of Electrical Engineering,Department of Physics & Astronomy, and the Center forImaging Science at RIT.In November, 1993, postdoc Umin Lee left the Universityof Rochester to accept a position at the EcoleNormale Superieure, in Lyon, France. Dr. Lee is continuinghis collaboration with Rochester astronomers, completinga study with Van Horn of the global oscillationmodes potentially excitable during the impacts of fragmentsof Comet Shoemaker-Levy 9 with Jupiter. In addition,he is currently finishing work on the effects ofsuperfluidity upon the global oscillation modes of neutronstars in collaboration with Richard Epstein (LosAlamos), Tim Collins (Rochester), and Van Horn.Research Associate Fran~ois PichC left the near IRgroup in June 1994 after a 1112 year stay. He has taken aposition at the University of Cambridge, UK and will bedeveloping new instrumentation to avoid the OH emissionbands in the near IR. He continues to collaboratewith the near IR group in his studies of the outflows fromYoung Stellar Objects, such as L1157.Alexander G. Muslimov completed his second yearas a research associate and instructor in July 1994, withsupport from an NSF grant. During the academic year1994-95 he will continue as Assistant Professor. In June1995 he will move to the Institut fur Astrophysik und ExtraterrestrischeForschung der Universitat, Bonn (Germany)with the support of a Humboldt fellowship.Jian Wu, a doctoral candidate in the EE department,completed his first year with the near IR groupthis past year as a part time engineer and scientist. He isresponsible for the test and evaluation of 5 micron cutoffHgCdTe 256 x 256 arrays from Rockwell Thousand OaksScience Center.Bradley Marazas is in his third year as Engineer withthe group.Hans Deeg joined the detector group at RIT inSeptember 1993 after completing his PhD in Astrophysicsat the University of New Mexico. He is stuydingthe performance of CCD arrays and the IMF of youngclusters.William Cirillo joined the detector group at RIT asan Associate Scientist with principal responsibilities beingthe development of camera control software.Peter Wilson (University of Sydney) was a visitingscientist in the department in August 1994, workingon problems in helioseismology and the solar cycle withThomas.Charles Gammie (U. Virginia) visited for two weeksin June 1994, working on aspects of ambipolar diffusionin the interstellar medium with Wardle.Kevin McFadden is in his third year as Programmer/Analystwith the Near IR group.Public tours were conducted at the Observatoryfrom June until the end of August by several undergraduateemployees: Rob Armstrong, Ronian Siew, TammyMiddleton, and Craig McMurtry. We are indebted toMarilee Kaye Montanaro for her excellent handling oftour arrangements and public relations for the Observatory,and to Kurt Holmes, carrying on in his father's finetradition as Observatory Supervisor.Marilee Kaye Montanaro, Administrative ResearchCoordinator for Astronomy, has efficiently handled themany administrative tasks for the group.2 Undergraduate EducationIn the second year of an NSF ILI grant, Meisel continuedwork using portable CCD cameras in elementaryastronomy laboratories. A paper describing the first yearresults was given in the Education session of the AmericanAstronomical Society meeting in Washington D.C.,January 1994 (Meisel, Showers, Lang, et al. 1994). Thisin turn led to an invitation to do a 112 hour presentationbefore the National meeting of the American Associationof Physics Teachers at Notre Dame in August '94. Theproject has also led to the collaborative development ofastronomy laboratory exercises with two observatoriesand others are expected in the future.O American Astronomical SocietyProvided by the NASA Astrophysics Data System

562 ANNUAL REPORTSJames Muzerolle worked with the far-infrared astronomygroup this year, and wrote a senior thesis entitled"Infrared spectroscopy of shocks in the DR21 andCepheus A molecular outflows," under Watson's direction.On the strength of this work he was runner-up inour department's annual Stoddard Prize competition.Senior undergraduate Tammy Middleton joined Watson'sgroup in the summer of 1994. She has been workingwith Raines and Watson on characterization of farinfrareddetectors and arrays.Craig McMurtry completed his senior thesis "NearInfrared Observations of the Star Formation RegionAFGL 6336 S" under Forrest. It was based on near IRimages acquired at the 1.5m Mount Lemmon ObservingFacility. He has begun graduate work in the PhysicsDepartment at U. Wyoming and is working for C.E.Woodward there. He continues to collaborate with theIR group during observing runs at the 2.3m WyomingInfrared Observatory.Bernie Sklanka completed his senior thesis "A NearInfrared Study of the BFS 56 Star Formation Region"under Forrest. He also wrote "An Overview of ObservationalTechniques for C.E. Kenneth Mees Observatoryand the Santa Barbara Instrumentation Group ST-6CCD Camera" which described his experiences imagingthe S 106 in the Ha line. He has gone to graduate schoolin Engineering at Penn State.Craig McMurtry, Bernie Sklanka, Abbas Tahir, RobArmstrong, and Ronian Siew worked in the near IR labover the summer of 1994. They helped develop new IRinstrumentation and organized the IR observational database. McMurtry and Sklanka also took part in the testingand evaluationpf 256 x 256 InSb and HgCdTe arraysunder the supervision of Brad Marazas and JianWu. Abbas began the design in Zemax and AutoCADof the cross-dispersed 1-5 micron echelette spectrometer(Xchel) .Undergrads Armstrong and Siew, along with gradstudents Jennifer Goetz and David May used the upgradedST-4X SBIG CCD camera at the 14" Wilmotobservatory to record the appearance of Jupiter in red,green, and blue bands during its collision with cometShoemaker/Levy in July 1994. Dark spots correspondingto impact sites were detected.A1 Pieterman spendt the summer of 1994 using theRIT 2kx2k CCD camera at the Mees Observatory studyingthe limits to accurate photometry of selected fields.He is continuing his efforts in his senior year at the Centerfor Imaging Science at RIT.3 Graduate EducationJohn Bloomer, Matt Guptill, Nick Raines and ShobitaSatyapal are graduate students in the Far InfraredGroup, working with Watson on far-infrared detector developmentfor SIRTF, imaging far-infrared spectrometerdevelopment, and infrared and millimeter wave spectrallineimagery of galaxies.Matt Guptill has taken a year's leave from his NASAGraduate Researchers Fellowship in Watson's group inorder to spend a year working at Rockwell (Anaheim).At Rockwell he is involved in the epitaxial growth andprocessing of Ge:Ga BIB far-infrared detector arrays, underJim Huffman's direction. His presence at Rockwellhas boosted considerably the detector fabrication activitiesof the Rochester-Rockwell-JPL collaboration responsiblefor the development of these devices for SIRTF,and has provided him the opportunity of including everyaspect of building, testing and using the arrays inhis thesis.Tim Collins completed his research on the effects ofsuperfluidity on nonradial spheroidal oscillations of neutronstars, in collaboration with Van Horn, Lee, and R.Epstein (Los Alamos). He presented a poster paper onthis work at the 184th meeting of the AAS (Collins et a1.1994). Collins also began his Ph.D. thesis research, investigatingthe boundary layers of accretion disks aroundwhite dwarfs in cataclysmic binaries. This research examinesthe possibility that quasiperiodic oscillations anddwarf-nova oscillations might both be driven by instabilitiesin the boundary layer. To this end he has createdsteady-state boundary layer and disk models in the fashionof both Lightman (1974) and Lioure and Le Contel(1994)' and is currently investigating the stability of theboundary layer. This work is being supervised jointly byVan Horn and Wardle.Guy Delamarter completed his first year of graduatestudy and his work with Van Horn on core formation interrestrial planets. He is now working with Wardle onshock waves in molecular clouds.J. Andrew Markiel is conducting his Ph.D. thesisresearch with Thomas and Van Horn, studying timedependentdynamo models operating in the surface convectionzones of white dwarfs. The goal of this research isto determine the conditions under which this process cangenerate magnetic fields with the strength and variabilitytimescale, e.g., which are inferred from the observationsof GD 358 (Winget et al. 1994). The preliminary resultsappear very promising, and the three investigatorshave recently published a short paper describing them(Markiel, Thomas, and Van Horn 1994) as a companionto the observational paper by the Texas group.Anthony Perez-Miller completed his first year ofgraduate study and is now working with Wardle, studyingthe effects of dust grains on shocks in molecularclouds.Colin Roald continued his research into nonlinearaperiodic solar dynamo models after passing his preliminaryexamination in September 1993. Working withThomas, he is developing a simple model with the dynamonumber and the magnetic Reynolds number as freeparameters. Currently he is attempting to map out thebifurcation boundaries in this two-dimensional parameterspace. Intermediate results of this project were presentedat a poster session at the MHD94 conference atHA0 (Boulder, Colorado) in August. He received hisM.A. in May, 1994.Don Stanchfield returned to the astrophysics theorygroup in the summer of 1994 after a leave of absence inO American Astronomical SocietyProvided by the NASA Astrophysics Data System

UNIVERSITY OF ROCHESTER 563the spring. With Thomas, he is analyzing the jump conditionsassociated with standing tube shocks in siphonflows.Eric Berton, a second-year graduate student in mechanicalengineering, joined the theoretical astrophysicsgroup in September 1994. He is working with Thomason magnetohydrodynamic problems associated with sunspots.Mark Swain is conducting his Ph.D. thesis researchon radio observations of the jets of galaxy NGC 353under the direction of Dr. Alan Bridle at the Charlottesville,Virginia, headquarters of the National RadioAstronomy Observatory. His internal (University ofRochester) advisers are Van Horn and Watson.Scott Libonate, Eric Howard, Jennifer Goetz, andDavid May are graduate students in Forrest and Pipher'sNear Infrared Group.Jennifer Goetz and David May have completed thefirst year of graduate school and begun investigationsof star formation regions through observations of characteristicspectral lines of [FeII], ionized hydrogen, andmolecular hydrogen.Libonate has completed his PhD thesis and will bedefending in November 1994. The thesis describes hisanalysis of near IR spectra and images of galactic tentersources and his design of a cross-dispersed echelettespectrometer for use with the excellent 256x256 InSbarrays available in the Near IR lab.Howard is continuing observations and analysis ofthe high mass star formation regions MonR2, K3-50a,NS14, S255-2 and S106. He is co-System Manager for theNear Infrared Group's Sun network and is supporting aWWW mosaic home page for the NIR group. The pagemay be accessed through the URL: htt~://sherman.~as.rochester.edu/URNIRhome.html.Steve Solomon is writing his Ph.D. thesis in absentiaon both his detector studies and on his study of thephysical conditions leading to excitation of the 3.28 pmdust emission feature in galactic and extragalactic objects.He is a research physicist in the detector divisionof Santa Barbara Research Center. Paula Turner isalso writing her Ph.D. thesis in abseniia, on the topic ofgalaxy-galaxy interactions: she is Assistant Professor ofAstronomy at Kenyon College.David Bretz continued his MS research at the Centerfor Imaging Science (RIT) into determining the initialmass function for the young cluster IC1805. BrianBacher is conducting his PhD research into the performanceof CID arrays and their use in a tip-tilt imagecorrection system for astronomy.4 Theoretical Astrophysics4.1 Solar PhysicsThomas and B. Montesinos (LAEFF, Madrid) continuedtheir theoretical work on siphon flows in solarmagnetic flux tubes. Recent observations by T. Rimmelesupport their siphon-flow model for the Evershed flow ina sunspot (Montesinos and Thomas 1993,Thomas andMontesinos 1993). This model has now been improvedto allow for flux tubes extending beyond the penumbralboundary into the surrounding photosphere. In a reviewof work on the Evershed effect, Thomas (1994) concludedthat proposed mechanisms based on small-scale wavesare not tenable and that the siphon-flow mechanism offersthe best explanation of the observations.Stanchfield and Thomas are investigating the structureof tube shocks in flows in magnetic flux tubes. Theyhave studied the one-dimensional jump conditions forthese shocks and have also shown that the thickness ofthese shocks is on the order of the flux tube diameter.4.2 Planetary PhysicsVan Horn and Lee (1993) and Lee and Van Horn(1994) extended earlier calculations by Lee and his collaboratorson the global oscillation spectrum of the giantplanet Jupiter to estimate the amplitudes of the oscillationmodes excited during the July 1994 collision ofComet Shoemaker-Levy 9 with Jupiter. They are currentlyawaiting the analyses of these data to see whetheror not any of the global modes were excited during thisevent. If so, they expect the mode spectrum to containevidence for or against the existence of a first-order"plasma phase transition" from the neutral molecular Hasurface layers to the ionized, metallic hydrogen interior.4.3 Low-Mass Binary StarsMuslimov has been studying the evolution of lowmassbinaries with neutron stars, and mechanisms ofGamma-ray production by newly discovered Gamma-raypulsars. Muslimov and Sarna (1993) have computed evolutionof the low-mass binary with 1.4 Mo neutron staras a compact companion and 1 Ma red dwarf as a donorstar. They have found that at the late stage of evolution,before the donor star reaches the minimum massN 0.2 Ma and shrinks within its Roche lobe, the donorstar undergoes 45 relatively short stages of episodicmass loss with approximately the Eddington rate. Thedetailed analysis of this effect of episodic mass loss inlow-mass binaries is in progress.Sarna, Lee, and Muslimov (1993, 1994) have investigatedthe pulsations of the red-dwarf companionof the neutron star in a low-mass binary. The illuminationof the donor star by the pulsar's high-energy,non-thermal radiation and relativistic wind may substantiallyaffect its internal structure and, e.g., result inthe oscillation spectrum qualitatively different from thatof its ZAMS counterpart. They have calculated tidallyforced gravity modes for the different degrees of the nonsunchronizationbetween the orbital rotation and spin rotationof the red-dwarf component. These investigatorshave suggested that the tidally induced oscillations maytrigger the Roche-lobe overflows and sudden mass lossby the donor star, and that this effect may be relevantto the y- and X-ray bursting activity in low-mass binaries.Muslimov has suggested that the electrodynamicsof pulsar polar cap regions incorporating the effect ofdragging of inertaal frames of reference on the accelerat-O American Astronomical SocietyProvided by the NASA Astrophysics Data System

564 ANNUAL REPORTSing electric field may help to advance our study of themechanisms of 7-ray production by Vela-type pulsars.He has illustrated the idea for a neutron star, such asin PSR 1706-44, with the the rotation period 0.1 s andsurface magnetic field 3 x 1012 G. His preliminary estimatesappear very promising, and he reported themat the Aspen Winter Conference on Millisecond Pulsars(see Muslimov 1994~).4.4 Properties of Dense MatterVan Horn and Ichimaru (1993) have published theproceedings of an August 1992 conference on the physicsof dense matter held at the University of Rochester. VanHorn (1994) has more recently published a discussion ofdense matter equations of state in calculations of stellarstructure and evolution.Van Horn and Yu. K. Kurilenkov have begun a collaborationto apply the results of laboratory investigationsof the optical properties of dense matter to astrophysicalapplications. Several poster papers have alreadybeen presented (Kurilenkov and Van Horn 1994a,b; Kurilenkov, Van Horn, and Skowronek 1994), anda number of longer papers are currently in preparation(c.f. Van Horn and Kurilenkov 1994). The goal of thiswork is to investigate the effects of plasma dispersionupon the transfer of radiation in dense plasmas, to calculatethe Rosseland mean opacity under conditions whereliwp/kT > 1, and to include the effects of the modifiedatomic energy level structures in dens plasmas upon theRosseland mean opacity.New calculations have also been performed for nuclearreaction rates at high densities. Ogata, Ichimaru,and Van Horn (1993) have extended results by Ogata,Iyetomi and Ichimaru (1991) to the general calculationof strong screening of thermonuclear reaction rates in binaryionic mixtures (BIMs). The detailed Monte Carloca1culations on which these new rates are based showthat the enhancement of nuclear reaction rates may besignificantly larger or smaller than previous results, dependingupon the relative concentrations of the ions withlarger and with smaller nuclear charges.Ogata et al. (1993a, b) have also computed newphase diagrams for dense, multi-ionic matter. This workwas motivated by an interest in the energetic consequencesof phase separation for the ages of the coolestwhite dwarf stars. Without the energy released duringphase spearation, the best estimates for the ages of thesestars are N 9 Gyr, much less than other estimates for theage of the Milky Way Galaxy. The new calculations indicatethat phase separation, especially of Ne from C inthe dense core of a white dwarf, can prolong the coolingtime by as much as - 6 Gyr. Whether this large an increasecan occur in the multa-ionic plasma within a realwhite dwarf remains to be seen, however.4.5 White DwarfsWinget et al. (1994) have discovered that the oscillationspectrum of the prototypical He-atmosphere whitedwarf GD 358 exhibits evidence for weak, - lo3 Gmagnetic fields, which appear to vary on a timescaleN months. This clearly suggests that a dynamo processmay be operating in the surface convection zone ofthis star. Markiel et a!. (1993, 1994) have demonstratedthat a time-dependent dynamo can indeed operate in awhite-dwarf convection zone, producing fields strengthsas large as - lo4 G, with a dynamo cycle period - years.More extensive theoretical investigations are currently inprogress as part of Markiel's Ph.D. thesis.Muslimov, Van Horn, and Wood (1994) have recentlyextended earlier calculations of magnetic-fieldevolution in white dwarfs to include the Hall effect. Inparticular, they have explored the simplest case in whichthe Hall effect changes the time-evolution of the field:the case of a cooling white dwarf possessing a strong(- lo9 G) internal toroidal magnetic field as well aspoloidal dipole and quadrupole components. Due to theHall effect the equations describing magnetic field evolutiondepend non-linearly upon the field strength. Thisin turn couples the field-decay modes. Muslimov et a1.have found that under these conditions, the evolution ofthe poloidal field is strongly affected by the presence ofthe postulated strong toroidal field.4.6 Neutron StarsEpstein (1988) has previously discussed the effectsof superfluidity upon the oscillations of neutron stars,using a short-wavelength approximation for his calculations.Van Horn and Epstein (1990) subsequently extendedthis work to include the global nonradial toroidaloscillation modes, which are generalizations of Epstein'stransverse waves. Superfluidity increases the propagationspeed of transverse waves, and this increases thetoroidal oscillation frequencies significantly over the resultsobtained neglecting superfluidity. Lee et al. (1994)and Collins et al. (1994a, b) have now extended these resultsto include the effects of superfluidity on the globalspheroidal oscillation modes of neutron stars, and VanHorn et al. (1994) have discussed possible future usesof observations of neutron-star oscillations as potentialprobes of the microscopic physics of matter at ultra-highdensities.Haensel, Urpin, and Yakovlev (1988) showed thatin the high magnetic fields B at the surfaces of pulsars,the generalized "Ohm's Law" that governs fields decaydepends nonlinearly on B. As a result, the timescalefor field dissipation may be only - lo6 years, ratherthan exceeding the Hubble time. Muslimov and VanHorn (1994) have recently explored this process usinga more detailed model than that employed by Haenselet al. They find that the combination of the nonlinearfield-dependence and the temperature sensitivity of thetransport coefficients indeed leads to rapid dissipation ofpoloidal magnetic fields, with a timescale - lo5 years, ifthe rapid cooling produced by the direct Urca processactually occurs.Muslimov (1994a) has extended his previous studyof the magnetic field evolution in neutron stars to includethe Hall effect and complexity of the magnetic field. HeO American Astronomical SocietyProvided by the NASA Astrophysics Data System

UNIVERSITY OF ROCHESTER 565has found that the Hall effect may substantially affectevolution of the poloidal components of the magneticfield in neutron stars. Recently, he has also proposed(Muslimov 199413) one of the possible schemes for theevolution of the magnetic field in millisecond pulsars. Hehas assumed that the magnetic field initially occupies theneutron star crust and outer core with superconductingnucleons, and that the magnetic field in a superconductingcore is organized in a form of flux tubes. Also, hehas assumed that there is "strong" interaction betweenneutron and proton vortices in a core of a neutron star.He has calculated evolution of the surface value of themagnetic field strength and has shown that it declinesapproximately 10 times during the first - 100 Myr, thenit rapidly decays by a factor of 10' - lo3 and at t 21Gyr enters a residual value ranging from to loA3times the initial value of the magnetic field strength.4.7 PulsarsChen studied radio pulse properties of millisecondpulsars. He proposed that radio emission of a millisecond(rns) pulsar consists of two components, a narrow oneand a broad one, according to the observed pulse width.The former is associated with the fastest ms pulsars,and the latter dominates the radio emission of relativelyslower pulsars. It seems that the morphology of the radiopulse profile correlates with a pulsar's magnetic fieldat light cylinder. The broad component appears to originateat N 113 - 114 of the light cylinder (rlc = cP/2n),where the local magnetic field is 105-6 G, which issimilar to that associated with the conal components ofcanonical radio pulsars. Chen noted that the magneticfields at the light cylinder of the disk-populated ms pulsarswith dominant broad components tend to be a constant,e.g., Blc = 1 0 ~ '.'. G. ~ This ~ empirical law maybe used to estimate magnetic field strengths of ms pulsarsin globular clusters which have similar radio pulses.Chen and S. Colgate (Los Alamos) have studiedthe observed circumstellar rings around the famous SN1987A. This circumstellar ring is extraordinarily symmetric,localized in space and in velocity. They postulatethat this degree of localization in phase space couldmost likely happen by the merger of two massive binarystars forming the progenitor of the supernova. The formationof a neutron star with a period as short as fewmilliseconds is then a natural consequence of the corecollapse.4.8 Accretion DisksWardle is continuing his collaboration with A. Konigl(U. Chicago) to calculate the structure of magnetizedprotostellar accretion disks that may power centrifugallydriven outflows (Wardle and Konigl 1993). The regimein which dust grains are the dominant charge carriersis currently under investigation. In this case the bulkof the disk material is magnetically passive because itis unable to support a significant current. Close to thedisk surfaces, where the gas density (and resistivity) islower, the coupling between the disk material and mag-netic field is sufficient to initiate a disk wind as before.An exploration of parameter space is currently underway.MacLow, Norman, Konigl and Wardle (1994) haveincorporated ambipolar diffusion into the ZEUS mhdcode and run some numerical tests: the gravitationalcollapse of a magnetized slab, the formation and steadystructure of an oblique C-type shock, and the developmentof the Balbus-Hawley mechanism in a magnetized,weakly-ionized accretion disk.Wardle is carrying out a linear analysis of the Balbus-Hawley instability in a weakly-ionized accretion in thecase that the magnetic and thermal pressures are comparableat the disk midplane. He is also investigating thestability of the disk-wind solutions found with Konigl.Collins, Van Horn, and Wardle continued their studyof the boundary layer between the white dwarf and theaccretion disk in cataclysmic variables. The investigationhas included an analytical and numerical study oflocal instabilities in the Keplerian part of the disk and inthe boundary layer, identifying instabilities which maybe responsible for the quasiperiodic and dwarf-nova 0scillationsobserved in many cataclysmic variables. Theyhave also created state-of-the-art alpha disk models inthe manner of Lightman (1974) and boundary layer modelssimilar to those of Lioure and Le Contel (1994). Thiswill allow a global numerical stability analysis of theboundary layer.4.9 The Galactic CenterYusef-Zadeh, Cotton, Wardle, Melia and Roberts(1994) presented VLA A20 crn observations of the angularbroadening of Sgr A* at the Galactic Center. Thescatter-broadened image shows an East-West elongationwith an axial ratio of 0.56 f 0.22, consistent with VLBAmeasurements at shorter wavelengths. They suggestthat scattering arises from anisotropic MHD turbulencein the thin ionized skins of clouds lying within 100 pc ofthe galactic center. The thickness of the layers, 10-3.5pc, provides an outer turbulent scale much less thanthe pc scale usually assumed and allows the scatteringmedium to lie much closer to the Galactic Center withoutviolating the constraints of free-free emissivity orabsorptivity.In a related investigation, Yusef-Zadeh (Northwestern)and Wardle are examining the spatial variation ofrotation measure along one of the Galactic Center nonthermalfilaments. The aim of this study is to relate thestatistical properties of the rotation measure to the fluctuationsin magnetic field and electron density close tothe Galactic Center.4.10 Shock Waves in Molecular CloudsDelamarter and Wardle have calculated the steadystructure of oblique, J-type shocks. A global stabilityanalysis will determine whether the precursors of theseshocks are susceptible to the instability known to existin Gtype shocks.Perez-Miller and Wardle have investigated the effectO American Astronomical SocietyProvided by the NASA Astrophysics Data System

566 ANNUAL REPORTSof dust grains on the structure of oblique C-type shockwaves. A recent paper by Pilipp and Hartquist (1994)shows that such shocks are not coplanar. Equations describingthe shock structure have been derived for anarbitrary number of charged fluids (e.g. ions, electronsand grains), and solutions will be found for shock wavespropagating in diffuse and dense interstellar clouds fordifferent grain populations.4.11 Positron Production in Shocked InterstellarCloudsHelfer is constructing a model for positron productionin shocked interstellar clouds following the developmentof a sucessful model for antiproton productionby Helfer & Savedoff (1992). That model used diffusiveacceleration of primary CR protons by shocks in suchclouds. The accelerated protons produce positrons frompion decay in excess of the observed 1 - 10 GeV positronflux by a factor of up to four. Most probably, this excessresults from ignoring bremsstrahlung losses in theshocked cloud. A model allowing for energy-dependentstorage times and radiative losses within the shockedcloud residue is being developed. It is necessary to includethe rapid decay of very short scale magnetic fieldfluctuations in the clouds (see Kulsrud & Pearce 1969;Helfer 1993). Estimates of the frequencies of occurancesof intermediate-scaled fluctuations in the post shockedclouds are underway in a separate investigation.The 'observed' positron flux in the 0.2 - 1 GeV rangecannot be matched; however we note that, for this energyrange, the positron flux directly inferred from CR leptonobservations uses a large (and uncertain) correction forsolar modulation effects and the lepton flux inferred fromgalactic low frequency radio radiation is suspect becauseof the use of inapropriate antenna patterns.5 Observational AstronomyThere are two observational infrared astronomygroups at the University of Rochester, the near infraredgroup (faculty supervisors: Forrest and Pipher) and thefar infrared group (faculty supervisor: Watson). Thenear infrared group has been developing InSb detectorarrays for SIRTF, and exploits them in a near IR 256 x256 InSb camera in ground-based activity. The camerahas fixed filters covering the 1 - 5.5 pm range, as well asCVF (circular variable filter) sections at resolutions of1 - 2%. Primary studies at the WIRO 2.3-m telescopeand the Mt. Lemmon 1.5-m telescope include an investigationof the nature of young stellar objects, and ofextragalactic nuclei and starburst regions. Rochester'sinfrared astronomy groups continue to work with groupsat the Smithsonian National Air and Space Museum(NASM), the Naval Research Laboratory (NRL), andthe Wyoming Infrared Observatory (WIRO) on infraredspectral-line imaging of Galactic star-formation regionsand starburst and Seyfert galaxies. Their observationsinvolve the use of the Rochester Third Generation Near-Infrared Array Camera, with a 256x256 InSb/DRO detectorarray, along with scanning Fabry-Perot spectrom-eters belonging to NASM and NRL, on the 2.2 meterWIRO telescope. This Infrared Spectroscopic Imaging(ISI) team includes W.J. Forrest, E. Howard, S. Libonate,F. PichC, J.L. Pipher, S.N. Raines, S. Satyapal andD.M. Watson (Rochester), M.A. Greenhouse and H.A.Smith (NASM), J. Fischer and K.L. Thompson (NRL)and T. Hodge, C.R. McMurtry and C.E. Woodward(WIRO).In addition to this activity, Thomas conducts solarobservations at the NOAO Sac Peak Observatory, andMees Associates Ninkov and Meisel conduct optical CCDobservations at the C.E.K. Mees Observatory, in Hawaii,and at MIRA (in California).5.1 The SunThomas and B. Lites (HAO, Boulder) carried outobservations of dynamical phenomena in sunspots usingthe Vacuum Tower Telescope, Advanced Stokes Polarimeter,and Universal Birefringent Filter at NSO(Sacramento Peak) in October 1993. They obtained severalgood data sets which are now being reduced and analyzedto give time series of Doppler velocity and vectormagnetic fields in a sunspot and the surrounding activeregion. These time series will be used to study sunspotseismology and the Evershed flow.5.2 Bolide AIDAMeisel continued a research collaboration with V.Getman (Tadjik Astronomical Institute) and J. Mathews(Penn State University, Communications and SpaceResearch Laboratory) on Bolide AIDA. This object appearedover Puerto Rico in April 1989 and informationwas obtained with seven different instruments. The finaldata analysis indicates this object was quite unusual,perhaps even unique. A paper describing this object isin preparation for presentation at the Division of PlanetarySciences of the American Astronomical Society, FallMeeting in Washington DC as well as publication theIcarus, the Planetary Science Journal (Meisel, Getman,Mathews, et al., 1994).5.3 Hubble's Variable NebulaWork continues at the Mees Observatory on Hubble'sVariable Nebula. Because of poor observing weather,only a limited number of images could be obtained. Preliminaryreduction of these images indicate that SII emissionseems to be concentrated around R Mon, while H-alpha is more wide-spread.5.4 The Comet Levy-Shoemaker Jupiter ImpactsOptical color video observations were made by Meiselat the Mees Observatory during the B impact event andprior to the F impact event. The remaining Mees timeduring the impact period was given to Zoran Ninkovand Roger Easton of RIT for taking optical CCD imagesin narrowband filters including the 8900 methaneband. All images obtained are being analyzed. AdditionalCCD images were obtained by undergraduate andO American Astronomical SocietyProvided by the NASA Astrophysics Data System

UNIVERSITY OF ROCHESTER 567graduate students in the Department using the campus14" telescope (the Wilmot Observatory).The near infrared group (Forrest and Pipher) collaboratedwith Howell and Woodward (Wyoming), Orton(JPL), Nicholson (Cornell), and Gehrz (Minnesota) toobtain IR images of the Comet Levy-Shoemaker Jupiterimpacts, and of the aftermath disturbances of Jupiter, inan observing run at WIRO from 13-24 July, 1994. Fastphotometry of impacts available at that site (B, U, V),as well as 2% spectral resolution images at a variety ofwavelengths (generally from 4 to 2.9 pm, 2.2 to 1.9 pm,and 1.8 to 1.6 pm) were obtained. Nothing significantwas seen at the time of the impacts, although there wereobservable spots later for the U and V sites, but not forthe B site. Other impacts were not available at WIRO:the various disturbances from other impacts were monitoredthrought the run. The only obvious spectral featurewas a large brightness in the Q spot's first rotationaround Jupiter at a wavelength near 3.4 pm. Emissionat this wavelength is a signature of hydrocarbon emission.In addition to the 2% spectral monitoring, imagesin the 4.7 pm narrow band were obtained, where thermalemission from deep within the Jovian atmospherecan be seen. The structure in these images was mostamazing. Thermal emission was not detected from anyof the impact sites, but there was a suggestive thermalring around one of the major spots. This type of ringis seen around the Great Red spot. This work is still inprogress.5.5 Observations of Star Formation Regions andNebulaeHoward, Pipher and Forrest (1994) report on nearinfrared imaging of the MonR2 high mass star formationregion at H, K, L" broad-band wavelengths, as wellas in emission lines at Bra and 7, and in dust emissionfeatures at 3.29 and 3.4 pm. These data allowed determinationof the extinction at a 1" spatial scale in theregion, and led to the development of a torus model forthe dense molecular gas surrounding the HI1 region. The3.29 and 3.4 pm dust feature emission coincides with the2.2 pm scattering ring.The IS1 team has now obtained a large number ofimages of prominent young-stellar-object (YSO) ouflowregions in broadband continuum light and spectral linesincluding [Fe 111 1.64 pm, H2 v = 1-0 S(l) 2.12 pm andH Bry 2.17 pm. Among the regions imaged are the"classic" molecular shock regions Orion-KL, NGC 7538,Cepheus A, L1551 and DR21, along with lesser-knownobjects such as L1157. A typical result is that in theGGD 37 region (Cepheus A West), in which the shockappears as a lobe composed of many arcs and filaments,in each case composed of a molecular hydrogen componentnestled about a [Fe 111 component which lies closerto the outflow source. The image thus shows an unambiguousand detailed separation between the cloud shock(shown in molecular hydrogen) and wind shock (shownin [Fe II]), for the first time. The Hz and [FeII] emissionin CepA outline separate velocity lobes pointing to thesource of excitation of CepA, an object not detected inthe near IR. These data are being analysed at present(Forrest et al. in preparation). Several areas in the OrionOMC-1 region are also being studied in these same diagnosticlines: in particular, the 'finger'-like protruberancesdescribed by Burton and Allen (1994) are beinginvestigated. PichC et al. (1993) describe the state of Hagas in L1448, one of the youngest bipolar molecular outflowsknown, through imaging in the Hz 2.122 pm line aswell as the 1-0 S(0) line at 2.223 pm. A surprising rangeof line flux ratios was found, encompassing dissociativeand non-dissociative shocks. A similar study of L1157has begun.Howard, Pipher, Forrest (1993) report on preliminaryJ, H, K, Bry, Bra and 3.29 pm dust emission imagingof K3-50, a compact HI1 region complex. A paperwill be written on K3-50 incorporating further observationsat higher spatial and spectral resolution. Alsoin progress is a paper on the star formation region S255which has also been studied in a similar manner. Howardis investigating high mass star formation regions as partof his PhD thesis research.PichC, Howard and Pipher (1994a) have imagedin Hz (2.122 pm) the energetic young stellar objectNGC 2264G and associated Herbig Haro object (HH124)with the Rochester array camera at Mt. Lemmon InfraredObservatory. The outflow driving source (IRAS06382+1017) is deeply embedded near the symmetrycenter of the outflow, and is associated with an infraredreflection nebula. Bry emission probably associated withthe IRAS source accretion disk was detected, and Hzemission associated with the outflow is found in a directiondiferent from the reflection nebula direction. TheHz spatial distribution is morphologically reminiscent ofbow shock wings.Hodge et al. (1993) has obtained observations ofseveral planetary nebulae in a hydrogen recombinationline, Hz line emission, and in certain unidentified linesat 2.199 and 2.287 pm (Geballe, Burton & Isaacman,1991), in order to investigate whether the responsiblespecies' emission coincides with the ionized region, orthe PDR. By this technique, in combination with otherobservations, the authors plan to deduce the excitationstate of the responsible species.Observation of young OB clusters such as IC1805,Berkeley 86 and NGC3296 have been obtained at BUR1using large format CCDs. These data are being analyzedby Ninkov and the RIT group to determine thepopulation of stars below the mass of B stars in suchclusters.5.6 The Galactic CenterLibonate, Pipher, Forrest, and Ashby (1994) presentlow and high resolution H and K band spectra of compact2.2 pm Galactic Center sources thought to be possibleyoung mass-losing stars, as well as comparison spectraof the LBV P Cygni and a WR star, HD 192163. TheBrackett line widths and flux ratios indicate that manyof these are strong stellar wind sources. Nine of theO American Astronomical SocietyProvided by the NASA Astrophysics Data System

ANNUAL REPORTSwind sources appear to contribute a significant fractionof the total luminosity of the Galactic center. Libonate(PhD thesis, 1994) further discusses Galactic center dataobtained with the Rochester IR cameras. He examinesthe evidence for a cusp in the stellar density, requiredby massive black hole models of the Galactic center luminosity,and finds no evidence for a cusp: he sets anupper limit on the putative black hole mass a factor often less than generally postulated. Libonate further developswind models to described the observed helium andhydrogen emission line spectra of Galactic center windsources. Although the WR stage is longer-lived than theLBV stage, Libonate only finds one WR star, as comparedwith 9 LBV stars in the Galactic center cluster.He uses this observation to time the beginning of thepresumed starburst at the Galactic center.5.7 Extragalactic ObjectsThe Rochester/NRL/NASM/Wyoming collaborationhas concentrated on observations of emission lines fromboth active and starburst galaxies. The IS1 team (Satyapalet al. 1993, 1994) report on high spatial resolution(1") and moderate spectral resolution (X/AX = 800)Pap and Bry Fabry-Perot imaging observations of thecentral kiloparsec of M82. These observations, in conjunctionwith new near-infrared broad-band imaging observations,are used to examine the extinction towardthe starburst region, the state of the ionized gas andthe nature of the stellar population. Enhancements inthe extinction-sensitive Pap /Bry flux ratio are foundto trace out the molecular lobes seen in CO, supportingthe assumption that we are observing a dense torussurrounding the central stellar clusters and HI1 regions.Using a non-uniform foreground screen model for thePap /Bry flux ratio, the derived visual extinction towardthe starburst region is found to vary from 2 to12 magnitudes, significantly smaller than is adopted inmost other studies of the stellar population in the starburstregion of M82. The extinction-corrected absoluteK magnitude in a 30/' aperture centered on the nucleusis found to be -22.0 mag. This is substantially fainterthan values previously adopted, amounting to as muchas a reduction of a factor of about 3 in the intrinsic Kluminosity. This may affect the inferred IMF for thestarburst region of M82. The recombination line imageswere used to estimate separately the contribution to thenear-infrared continuum bandpasses from free-free andfree-bound processes and the emission from dust. Thesesources of emission do not contribute appreciably to thetotal near-infrared continuum and thus it can confidentlybe assumed that this emission is dominated by starlight.In addition, they present narrow-band imaging observationsof the 3.29 pm unidentified dust feature. Theemission is seen to be well-correlated with the Bry emission.The ratio of the total far-infrared luminosity to thede-reddened 3.29 pm feature luminosity is found to be1340 f 260 for M82, significantly smaller than the ratioobtained using the uncorrected 3.29 pm feature flux(1690 f 200).Greenhouse et al. (1993) present images of M82 inthe [FeII] 1.64 pm line: surprisingly, the image of thestarburst core is quite diffuse, and shows little correspondencewith either Bry or PP images, or with supernovaremnants detected at radio wavelengths.Observations of other galaxy nuclei, at broad-bandwavelengths, in emission lines, and in the 3.29 pm featureemission, are presently being reduced. Turner (1994;PhD thesis, in preparation) is analyzing galaxy-galaxymergers.Watson and Guptill have continued their program ofmolecular observations of polar ring galaxies, and havedetected and partially mapped eight of a sample of tenof these objects in the CO J = 2-1 line, using the CaltechSubmillimeter Observatory. (Initial results are presentedby Watson et al., 1994.) In each case the molecularcomponent of the polar ring is substantial, comprising1-20 x 10' solar masses, and in some cases the molecularcomponent outweighs the neutral atomic component. Allof the galaxies detected show low to moderate star formationefficiency indices (0.1-10 La /Ma), much lowerthan that of other galaxy-interaction remnants such asstarburst galaxies (typically 200 La /Ma ). They will beextending the program during the next year by obtaininghigh-resolution, interferometric CO maps of their brightestsources, to facilitate detailed dynamical modelling ofthe rings and derivation of the underlying distributionof mass in host galaxy and halo.5.8 Observations of Binary StarsNinkov and Deeg, in collaboration with LauranceDoyle (NASA Ames) and Jean Schneider (Meudon Observatory)have made observations of eclipsing binarystars to study the feasibility of detecting transits of extrasolarplanets. A full campaign is planned for thespring of 1995 using observatories in Europe, the ContinentalUSA, Hawaii and Korea.6 Instrumentation6.1 Near Infrared CameraThe Rochester Near Infrared camera utilizes anSBRC 256 x 256 InSb array, the best one produced onthe SIRTF project (see below), run at an optimized temperatureof 26K. A cold filter wheel houses J, H, K, L",Mi, 3.3 pm filters, and two CVFs chosen from CVFscovering the H, K, L/M bands. A DSP-based array controller,in the backplane of a 486 microcomputer wasdeveloped at Rochester, as were various other systemcomponents (AID boards, special bias cards, preamps,110 board). Clocked drivers (level shifters), and otherbias cards were designed and built to Rochester specifications.A Sun IPC computer communicates with the486 computer via ethernet, and Sun programs (e.g. Vu-Fits) are used to view the data. Rochester programmeranalystMcFadden wrote a GUI for observing use: theobserving program is in C-Forth. Warm J/H and K -band FPs are interspersed in the optical path of theRochester spectrometer for higher spectral resolution.O American Astronomical SocietyProvided by the NASA Astrophysics Data System

UNIVERSITY OF ROCHESTER 569The FP computer communicates with the Camera computerto assure appropriate camera conditions for a givenFP observation.Plans to build an echellette IR spectrometer areunderway. Woodward (WIRO) will collaborate withRochester. Libonate has completed an optical design.6.2 Far-infrared Spectroscopic CameraAn imaging far-infrared Fabry-Perot spectroscopiccamera, based upon the 6 x 6 Ge:Ga BIB detector arrays,has been constructed at Rochester by Raines, Guptilland Watson. Its characteristics include four focal-planepixels per Airy disk at 160 microns; adjustable velocityresolution down to a minimum of 60 km/s; good instrumentthroughput and background-limited sensitivity.This instrument has been selected to fly on theNASA Kuiper Airborne Observatory next year to carryout a program of imaging observations of far-infraredmolecular lines in shicks associated with YSO outflows.7 Detectors7.1 Near IR Detector Array Test and EvaluationRochester, under the auspices of SIRTF grants, andseveral space oriented NASA grants, has been involvedin an extensive test and evaluation program for infrareddetector arrays. Our primary efforts have been expendedon the InSb arrays/multiplexers baselined for the SIRTFInfrared Array Camera. Currently, 256 x 256 InSb arrays,of low-doped material, bonded to the CRC 463multiplexer are being studied. Quantum efficiencies inexcess of 90%, dark currents < 1 e-/s, and multiplysampled noise of 12 e- have been obtained in one array,operating at 26K. We are planning to test an arraybonded to the CRC 744 multiplexer (10K operation) assoon as one is delivered, and are beginning to retrofit oursystem for test and evaluation of 1024 x 1024 AladdinInSb arrays.HgCdTe arrays, with -- 5 ,urn cut-off wavelength,produced by Rockwell International, Science Center arebeing tested by our group. To date, new process BPHand MBE HgCdTe seem most promising. Generationrecombinationlimited dark current at 55K has beenachieved with the BPH material.7.2 Ge:Ga BIB detector arrays and imagingspectrometerWatson and his group, with J.E. Huffman (Rockwell)and T.N. Krabach (JPL), continue to develop germaniumblocked-impurity-band (BIB) detector arrays, aradiation-hard planar detector technology developed foruse in the 50-200 micron channels of SIRTF. Currently6x6 and 4x16 arrays are produced, and achieve peakquantum efficiency up to 20% and dark current below100 e/s, suiting the requirements of the SIRTF instruments.Work this year has focused on improvement inthe photoresponse time constant of the detectors, whichhave hitherto been rather slow at low backgrounds, andupon modelling of the long-wavelength response and optimizationof the structure and doping. The latter detailscan be found in articles generated this year (Watson1994; Watson et a1. 1994).7.3 Visible-light ArraysTesting of large format CCD and CID arrays continuesin Ninkov's laboratory at RIT and results havebeen reported in Ninkov (1994), Ninkov, Tang and Carbone(1994), Ninkov, Tang and Easton (1994) and Deegand Ninkov (1995) under the support of NSF and NASAinstrumentation grants. The development of low noiseCID and Active Pixel Sensor CID devices will lead to aradiation hard sensor for space applications.PUBLICATIONSBurton, M.G. and Allen D.A. 1994, in Infrared Astronomywith Arrays: the Next Generation, I. McLean,Kluwer 61Collins, T. J. B., Van Horn, H. M., Lee, U., Epstein, R.1994, BAAS, 24, 878Collins, T. J. B., Lee, U., Epstein, R. I., Van Horn, H.M. 1994a, to be submitted to ApJCollins, T. J. B., Van Horn, H. M., Lee, U., Epstein, R.1994b, BAAS, 26, 878Deeg, H, and Ninkov, Z. 1995, accepted, Optical Engineering,JanuaryEpstein, R. 1988, ApJ, 333, 880Geballe T.R., Burton, M.G., and Isaacman, T. 1991,MNRAS 253,75Greenhouse, M.A., Thompson, K.L., Fischer, J., Woodward,C.E., Van Tassel, H.,, Satyapal, s., Forrest,W.J., Watson, D., Pipher, J.L. 1993, BAAS 25, 1412Haensel, P., Urpin, V. A., Yakovlev, D. G. 1990, A&A,229, 133Helfer, H L. 1993 News Letter of the ASNY, 4:4, 37(abst.)Helfer, H.L. and Savedoff, M.P. 1992 Astrop. & Sp. Sci.188, 299Hodge, T.M., Woodward, C.E., PichB, F., Forrest, W.J.,Libonate, S., Pipher, J.L., Raines, N., Satyapal, S.,Watson, D., Greenhouse, M.A., Smith, H., Fischer,J., Thompson, K.L., van Buren, D. 1993, BAAS 25,1370Howard, E.M., Pipher, J.L., and Forrest, W.J. 1993,BAAS 25, 1368Howard, E.M., Pipher, J .L. and Forrest, W.J. 1994, ApJ425,707Kulsrud,R. and Pearce, W. P. 1969 ApJ 156, p 455Kurilenkov, Yu. K., Van Horn, H. M. 1994a, in Proc.IAU Coll. 147: The Equation of State in Astrophysics,G. Chabrier and E. Schatzman, CambridgeUniversity Press: Cambridge 581O American Astronomical SocietyProvided by the NASA Astrophysics Data System

570 ANNUAL REPORTSKurilenkov, Yu. K.,Van Horn, H. M. 1994b, poster pa- Ogata, S., Ichimaru, S., Van Horn, H. M. 1993, ApJ,per to be published in 9th Topical Conference on 417, 265ktomic ~rocesses in Plasma, (San Antonio, Texas, Ogata, S., Iyetomi, H., Ichimaru, S. 1991, ApJ, 372, 25919-23 September 1993)Ogata, S., Iyetomi, H., Ichimaru, S., Van Horn, H. M.1993a, in Strongly Coupled Plasma Physics, H. M.Van Horn and S. Ichimaru University of RochesterPress:Rochester, NY, 53Kurilenkov, Yu. K., Van Horn, H. M., Skowronek, M.1994, poster paper, to be published in Proc. VIIInternational Workshop on the Physics of NonidealPlasmas (Universitat Rostock, Germany, 27 September- 1 October 1993)Lee, U., Collins, T. J. B., Epstein, R. I., Van Horn, H.M. 1994, in Proc. IAU Coll. 147: The Equation ofState in Astrophysics, G. Chabrier and E. Schatzman,Cambridge University Press: Cambridge 586Lee, U., Van Horn, H. M. 1994, ApJ, 428, L41Libonate, S.L., Pipher, J.L., Forrest, W.J., and Ashby,M. 1994, ApJ in pressLightman, A. P. 1974, ApJ, 194,419Lioure, A., Le Contel, 0. 1994, AA, 285, 185MacLow, M.-M., Norman, M. L., Konigl, A., Wardle, M.1994, ApJ, submittedMarkiel, J. A., Thomas, J. H., Van Horn, H. M. 1994,ApJ, 430, 834Markiel, J. A., Van Horn, H. M., Thomas, J. H. 1993,News Letter ASNY, 4:3 41Meisel, D., Getman, V. S., Mathews, J. D., Morton, Y.T., Zhou, QW., Roper, R. G., Marsden, B. G. 1994,26th Meeting of the Division for Planetary Sciencesof the AAS. Nov. 4, 1994 Washington D.C.Meisel, D., Showers, D., Lang, M., Emerling, B., Greenfield,M., Abe, W. 1994, BAAS, 25, 4, 1436Montesinos, B., and Thomas, J. H. 1993, ApJ, 402, 314Muslimov, A. G. 1994a, MNRAS, 267, 523Muslimov, A. G. 1994b, to be published in Aspen WinterConference on Millisecond Pulsard, D. Backer and M.TavaniMuslimov, A. G. 1994c, to be published in Aspen WinterConference on Millisecond Pulsard, D. Backer and M.TavaniMuslimov, A. G., Sarna, M. J. 1993, in The Evolution ofX-Ray Binaries, S. S. Hold and C. S. Day, AIP:NY,391Muslimov, A. G., Van Horn, H. M. 1994, in Proc. IAUColl. 147: The Equation of State in Astrophysics, G.Chabrier and E. Schatzman Cambridge UniversityPress: Cambridge, 591Muslimov, A. G., Van Horn, H. M., Wood, M. A. 1994,submitted to ApJNinkov, Z. 1994, AJ, 107, 1182Ninkov, Z., Tang, C., Carbone, J. 1994, Proc. SPIE,2198, 109Ninkov, Z., Tang, C., Easton, R. L. 1994, Proc. SPIE,298, 15Ogata, S., Iyetomi, H., Ichimaru, S., Van Horn, H. M.1993b, Phys. Rev. E, 48, 1344Pichk, F., Pipher, J.L., Raines, S.N., Thompson, K.L.,Hodge, T., Woodward, C.E., and Smith, H.A. 1993,BAAS 25, 1419Pichk, F., Howard, E.M., and Pipher J.L. 1994a, BAAS26, 931Pilipp, W., Hartquist, T. W. 1994, MNRAS, 267, 801Sarna, M. J., Lee, U., Muslimov, A. G. 1993 in Theevolution of X-Ray Binaries, S. S. Hold and C. S.Day, AIP:NY, 307Sarna, M. J., Lee, U., Muslimov, A. G. 1994, ApJ, 431,302Satyapal, S., Watson, D.M., Pipher, J.L., Forrest, W.J.,Coppenbarger, D., Raines, S.N., Libonate, S., Pichk,F., Greenhouse, M.A., Smith, H.A., Thompson, K.L.,Fischer, J., Woodward, C.E., Hodge, T. 1993 BAAS25, 1412Satyapal, S., Watson, D.M., Pipher, J.L., Forrest, W.J.,Coppenbarger, D., Raines, S.N., Libonate, S., Pichk,F., Greenhouse, M.A., Smith, H.A., Thompson, K.L.,Fischer, J., Woodward, C.E., Hodge, T. 1994, submittedto ApJThomas, J. H., and Montesinos B. 1993, ApJ, 407, 398Thomas, J. H. 1994, in Solar Surface Magnetism, R. J.Rutten and C. J. Schrijver, Dordrecht: Kluwer, 219Van Horn, H. M. 1994, in Proc. IAU Coll. 147: TheEquation of State in Astrophysics, G. Chabrier andE. Schatzman, Cambridge University Press: Cambridge,1.Van Horn, H. M., Epstein, R. I. 1990, BAAS, 22, 748Van Horn, H. M., Ichimaru, S. 1993, Strongly CoupledPlasma Physic, (University of Rochester Press:Rochester, NYVan Horn, H. M., Lee, U. 1993, BAAS, 25, 1331Van Horn, H. M., Lee, U., Epstein, R. I., Collins, T. J.B. 1994, to be published in Proc. Oji Seminar onElementary Processes in Dense Plasmas, S. OgataVan Horn, H. M., and Kurilenkov, Yu. K. 1994, to besubmitted to ApJWardle, M., Konigl, A. 1993, ApJ, 410, 218Watson, D.M. 1994, submitted to Phys. Rev. BWatson, D.M., Guptill, M.T. and Buchholz, L.M. 1994,AJ 420, L21.O American Astronomical SocietyProvided by the NASA Astrophysics Data System

Watson, D.M., Guptill, M.T., Huffman, J.E., Krabach,T.N. and Raines, S.N. 1994, Phys. Rev. B 49, 16361Winget, D. E., el al. 1994, ApJ, 430, 839Yusef-Zadeh, F., Cotton, W., Wardle, M., Melia, F.,Roberts, D. A. 1994, ApJ, in pressWilliam J. Forrest, DirectorUNIVERSITY OF ROCHESTERO American Astronomical SocietyProvided by the NASA Astrophysics Data System