Alicia Margarita Soderberg

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We present a new compilation of Type Ia supernovae (SNe Ia), a new data set of low-redshift nearby-Hubble-flow SNe, and new analysis procedures to workwith these heterogeneous compilations. This ‘‘Union’’ compilation of 414 SNe Ia, which reduces to 307 SNe after selection cuts, includes the recent large samples of SNe Ia from the Supernova Legacy Survey and(More)
Past studies have suggested that long-duration gamma-ray bursts have a 'standard' energy of E(gamma) approximately 10(51) erg in the ultra-relativistic ejecta, after correcting for asymmetries in the explosion ('jets'). But a group of sub-energetic bursts, including the peculiar GRB980425 associated with the supernova SN1998bw (E(gamma) approximately 10(48)(More)
Massive stars end their short lives in spectacular explosions--supernovae--that synthesize new elements and drive galaxy evolution. Historically, supernovae were discovered mainly through their 'delayed' optical light (some days after the burst of neutrinos that marks the actual event), preventing observations in the first moments following the explosion.(More)
Long-duration gamma-ray bursts (GRBs) are thought to result from the explosions of certain massive stars, and some are bright enough that they should be observable out to redshifts of z > 20 using current technology. Hitherto, the highest redshift measured for any object was z = 6.96, for a Lyman-alpha emitting galaxy. Here we report that GRB 090423 lies at(More)
We present detailed optical, X-ray and radio observations of the bright afterglow of the short gamma-ray burst 051221 obtained with Gemini, Swift/XRT, and the Very Large Array, as well as an optical spectrum from which we measure the redshift of the burst, z = 0.5459. At this redshift the isotropic-equivalent prompt energy release was about 2.4 × 10 51 erg,(More)
X iv :a st ro -p h/ 05 09 89 1v 3 9 N ov 2 00 5 The Progenitors of Short-Hard Gamma-Ray Bursts from an Extended Sample of Events Avishay Gal-Yam, Ehud Nakar, Eran O. Ofek, S. B. Cenko, S. R. Kulkarni, A. M. Soderberg, F. Harrison Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA91125 D. B. Fox Department of(More)
We have converted the Palomar 60-inch telescope (P60) from a classical night assistant-operated telescope to a fully robotic facility. The automated system, which has been operational since September 2004, is designed for moderately fast (t . 3 minutes) and sustained (R . 23 mag) observations of gamma-ray burst afterglows and other transient events. Routine(More)
Over the past decade, long-duration gamma-ray bursts (GRBs)--including the subclass of X-ray flashes (XRFs)--have been revealed to be a rare variety of type Ibc supernova. Although all these events result from the death of massive stars, the electromagnetic luminosities of GRBs and XRFs exceed those of ordinary type Ibc supernovae by many orders of(More)
We present preliminary results from the Caltech Core-Collapse Project (CCCP), a large observational program focused on the study of core-collapse SNe. Uniform, high-quality NIR and optical photometry and multi-epoch optical spectroscopy have been obtained using the 200” Hale and robotic 60” telescopes at Palomar, for a sample of 50 nearby core-collapse SNe.(More)
Over the past decade, our physical understanding of gamma-ray bursts (GRBs) has progressed rapidly, thanks to the discovery and observation of their long-lived afterglow emission. Long-duration (> 2 s) GRBs are associated with the explosive deaths of massive stars ('collapsars', ref. 1), which produce accompanying supernovae; the short-duration (< or = 2 s)(More)