[SEMINARI] GRB 101225A: a stellar murder on Christmas Day, Miguel Angel Aloy]

[Enric Marco]

Títol:GRB 101225A: a stellar murder on Christmas Day

Per:Miguel Ángel Aloy
De:Departament d'Astronomia i Astrofísica, Universitat de València

(Retransmisió de la seua xerrada des de l'IAC)

Seminari del departament d'Astronomia i Astrofísica
Dijous 15 desembre 2011
11:30

Resum
Long Gamma-Ray Bursts (GRBs) are the most dramatic examples of massive stellar deaths, 
usually associated with supernovae (Woosley et al. 2006). They release ultra-relativistic 
jets producing non-thermal emission through synchrotron radiation as they interact with the
 surrounding medium (Zhang et al. 2004). Here we report observations of the peculiar GRB 101225A
 (the 'Christmas burst'). Its gamma-ray emission was exceptionally long and followed by a bright X-ray
 transient with a hot thermal component and an unusual optical counterpart. During the first 10 days,
 the optical emission evolved as an expanding, cooling blackbody after which an additional component,
 consistent with a faint supernova, emerged. We determine its distance to 1.6 Gpc by fitting the 
spectral-energy distribution and light curve of the optical emission with a GRB-supernova template.
 Deep optical observations may have revealed a faint, unresolved host galaxy. Our proposed progenitor
 is a helium star-neutron star merger that underwent a common envelope phase expelling its hydrogen envelope.
 The resulting explosion created a GRB-like jet which gets thermalized by interacting with the dense, previously
 ejected material and thus creating the observed black-body, until finally the emission from the supernova dominated.
 An alternative explanation is a minor body falling onto a neutron star in the Galaxy (Campana et al. 2011).

http://celeste.uv.es/daa/seminari.php?id=1047

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Dr. Enric Marco
Departament d'Astronomia i Astrofísica
Facultat de Física
Universitat de València
C/  Dr. Moliner, 50
46100 Burjassot, Spain
Phone: (34)-96-354-3069
Fax:(34)-96-354-3084
enric.marco en uv.es
www.uv.es/marco
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-- 
/------------------------------------\
 Dr. Enric Marco
 Departament d'Astronomia i Astrofísica
 Facultat de Física
 Universitat de València
 C/  Dr. Moliner, 50
 46100 Burjassot, Spain
 Phone: (34)-96-354-3069
 Fax:(34)-96-354-3084
 enric.marco en uv.es
 http://www.uv.es/marco
 http://www.uv.es/aulaastronomia
 http://www.uv.es/daa
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