Universitat de - Departament d'Astronomia i Meteorologia ...

More documents

Recommendations

Info

14 Chapter 1. Introduction and background E N 1" MAR 27 APR 03 APR 09 APR 16 APR 23 APR 30 Figure 1.5: VLA multiepoch observations at 3.6 cm wavelength of the superluminal ejection of GRS 1915+105 in 1994. The approaching component, to the left, appeared to move at 1.25c and be brighter than the receding one, to the right, which moved with an apparent velocity of 0.65c (from Mirabel & Rodríguez 1994).
1.2. Microquasars 15 Special relativity effects: Doppler shift and boosting Taking into account that the plasma clouds move at relativistic speeds, there will be a shift in the observed to emitted wavelengths. The ratios of the observed (νa and νr) to emitted frequency (ν0) are given by the Doppler factors: δa = νa ν0 δr = νr ν0 = = 1 Γ(1 − β cos θ) 1 Γ(1 + β cos θ) , (1.14) , (1.15) where Γ is the bulk Lorentz factor given by Γ = (1 − β 2 ) −1/2 . δr is always smaller than 1, while δa is smaller than 1 for large values of θ and rises above 1 for small values of θ, i.e., when the jet is pointing to us. Hence, an eventually observed receding spectral line will always be red-shifted, while the blue or red-shift of the approaching one will depend on the ejection angle. If for a particular event we were able to measure a frequency shift in a spectral line produced in the plasmons, and also compute β cos θ from Eq. 1.8, we could then find β, and hence θ and D by using Eq. 1.8 and Eq. 1.9, respectively. This would allow us to solve for the whole parameters of an ejection. On the other hand, the measured flux densities of the approaching and receding clouds will also suffer from special relativity effects. The ratios of the observed (Sa and Sr) to emitted flux density (S0) from a twin pair of optically thin, isotropically emitting jets are given by: Sa S0 Sr S0 = δ k−α a , (1.16) = δ k−α r , (1.17) where k equals 2 for a continuous jet and 3 for discrete condensations, and α is the spectral index of the radio emission (Sν ∝ ν +α ). Typical values for α in the optically thin regime are between −0.5 and −1. Hence, the exponent in the equations above will typically be in the range 2.5–4. As a consequence, the detected flux density of the receding plasma cloud will be diminished (deboosting), while for the approaching one will depend on the angle, as the Doppler factor does, i.e., we will have deboosting for large angles and considerable boosting for small angles. Using these equations, the ratio of approaching to receding flux densities measured at equal distance from the core is: Sa Sr = k−α 1 + β cos θ 1 − β cos θ . (1.18)
Page 1:
UNIVERSITAT DE BARCELONA Departamen
Page 5:
Per a la meva neboda Blanca, que va
Page 8 and 9:
feina no presentada en aquesta tesi
Page 10 and 11: desfogar-nos conjuntament, per la s
Page 12 and 13: From the scientifical point of view
Page 14 and 15: Gràcies a la meva germana Nàdia,
Page 16 and 17: ii CONTENTS I Discovery and study o
Page 18 and 19: iv CONTENTS II A search for new mic
Page 20 and 21: vi CONTENTS
Page 22 and 23: viii Resum de la tesi d’Eddington
Page 24 and 25: x Resum de la tesi imprescindible p
Page 26 and 27: xii Resum de la tesi dels sistemes
Page 28 and 29: xiv Resum de la tesi un comportamen
Page 30 and 31: xvi Resum de la tesi MilliARC SEC 4
Page 32 and 33: xviii Resum de la tesi per poder de
Page 34 and 35: xx Resum de la tesi valors força s
Page 36 and 37: xxii Resum de la tesi 2. D’entre
Page 38 and 39: xxiv Resum de la tesi pano Alemán
Page 40 and 41: xxvi Resum de la tesi 3.3 Observaci
Page 42 and 43: xxviii Resum de la tesi habitual en
Page 44 and 45: xxx Resum de la tesi Per tant, si l
Page 46 and 47: xxxii BIBLIOGRAFIA
Page 48 and 49: 2 Chapter 1. Introduction and backg
Page 56 and 57: 10 Chapter 1. Introduction and back
Page 74 and 75: 28 BIBLIOGRAPHY Lewin, W. H. G., va
Page 76 and 77: 30 BIBLIOGRAPHY
Page 79 and 80: Chapter 2 Multiwavelength approach
Page 81 and 82: 2.3. An interesting target in the s
Page 83 and 84: 2.4. The radio counterpart: NVSS J1
Page 101 and 102: 2.5. The optical/IR star: LS 5039 5
Page 111 and 112:
2.6. The X-ray counterpart: RX J182
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
2.7. The γ-ray counterpart: 3EG J1
Page 123 and 124:
2.7. The γ-ray counterpart: 3EG J1
Page 125 and 126:
2.8. A proposed scenario to explain
Page 127 and 128:
Figure 2.23: Scenario where the mul
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
2.9. Conclusions 87 8. We have carr
Page 135 and 136:
Bibliography Blandford, R. D., & K
Page 137 and 138:
BIBLIOGRAPHY 91 Merck, M., Bertsch,
Page 139 and 140:
Chapter 3 LS 5039 as a runaway micr
Page 141 and 142:
3.1. Positions and proper motions 9
Page 143 and 144:
3.1. Positions and proper motions 9
Page 145 and 146:
3.3. The past trajectory of LS 5039
Page 147 and 148:
3.4. SNR G016.8−01.1 101 DECLINAT
Page 149 and 150:
3.4. SNR G016.8−01.1 103 Normaliz
Page 151 and 152:
3.4. SNR G016.8−01.1 105 Galactic
Page 153 and 154:
3.5. The H i surroundings of LS 503
Page 155 and 156:
3.6. Discussion 109 experienced a h
Page 157 and 158:
3.6. Discussion 111 At this point w
Page 159 and 160:
3.7. Conclusions 113 6. Finally, th
Page 161 and 162:
Bibliography Ankay, A., Kaper, L.,
Page 163 and 164:
BIBLIOGRAPHY 117 Schaerer, D., de K
Page 165:
Part II A search for new microquasa
Page 168 and 169:
122 Chapter 4. The cross-identifica
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
130 BIBLIOGRAPHY
Page 178 and 179:
132 Chapter 5. Radio and optical ob
Page 180 and 181:
DECLINATION (J2000) DECLINATION (J2
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
148 BIBLIOGRAPHY
Page 196 and 197:
150 Chapter 6. EVN and MERLIN obser
Page 198 and 199:
Page 200 and 201:
Page 202 and 203:
Page 204 and 205:
Page 206 and 207:
Page 208 and 209:
Page 210 and 211:
Page 212 and 213:
166 BIBLIOGRAPHY
Page 214 and 215:
¡¢ ¢ ¢ ¡¢ £¤ ¡¢ ¤ ¢
Page 217 and 218:
General conclusions 171 Since each
show all

Universitat de - Departament d'Astronomia i Meteorologia ...

Create successful ePaper yourself

Delete template?

Save as template?