Astrophysics - High Energy Astrophysical Phenomena

Calcium-rich Gap Transients in the Remote Outskirts of Galaxies

From the first two seasons of the Palomar Transient Factory, we identify three peculiar transients (PTF 09dav, PTF 10iuv, and PTF 11bij) with five distinguishing characteristics: peak luminosity in the gap between novae and supernovae (M$_R$ ≈ -15.5 …

Swift J2058.4+0516: Discovery of a Possible Second Relativistic Tidal Disruption Flare?

We report the discovery by the Swift hard X-ray monitor of the transient source Swift J2058.4+0516 (Sw J2058+05). Our multi-wavelength follow-up campaign uncovered a long-lived (duration >åisebox-0.5ex months), luminous X-ray (L $_X, iso$ ≈ 3 × …

PTF10iya: a short-lived, luminous flare from the nuclear region of a star-forming galaxy

We present the discovery and characterization of PTF10iya, a short-lived (Δt≈ 10 d, with an optical decay rate of ̃0.3 mag d$^-1$), luminous (? mag) transient source found by the Palomar Transient Factory. The ultraviolet/optical spectral energy …

Rapid, Machine-learned Resource Allocation: Application to High-redshift Gamma-Ray Burst Follow-up

As the number of observed gamma-ray bursts (GRBs) continues to grow, follow-up resources need to be used more efficiently in order to maximize science output from limited telescope time. As such, it is becoming increasingly important to rapidly …

SN 2010jp (PTF10aaxi): a jet in a Type II supernova

We present photometry and spectroscopy of the peculiar Type II supernova (SN) SN 2010jp, also named PTF10aaxi. The light curve exhibits a linear decline with a relatively low peak absolute magnitude of only -15.9 (unfiltered), and a low radioactive …

A Compact Degenerate Primary-star Progenitor of SN 2011fe

While a white dwarf (WD) is, from a theoretical perspective, the most plausible primary star of a Type Ia supernova (SN Ia), many other candidates have not been formally ruled out. Shock energy deposited in the envelope of any exploding primary …

The Gamma-Ray Burst - Supernova Connection

A preponderance of evidence links long-duration, soft-spectrum gamma-ray bursts (GRBs) with the death of massive stars. The observations of the GRB-supernova (SN) connection present the most direct evidence of this physical link. We summarize 30 …

Constraining Gamma-Ray Burst Emission Physics with Extensive Early-time, Multiband Follow-up

Understanding the origin and diversity of emission processes responsible for gamma-ray bursts (GRBs) remains a pressing challenge. While prompt and contemporaneous panchromatic observations have the potential to test predictions of the …

Exclusion of a luminous red giant as a companion star to the progenitor of supernova SN 2011fe

Type Ia supernovae are thought to result from a thermonuclear explosion of an accreting white dwarf in a binary system, but little is known of the precise nature of the companion star and the physical properties of the progenitor system. There are …

A faint optical flash in dust-obscured GRB 080603A: implications for GRB prompt emission mechanisms

We report the detection of a faint optical flash by the 2-m Faulkes Telescope North simultaneously with the second of two prompt γ-ray pulses in INTEGRAL gamma-ray burst (GRB) 080603A, beginning at t$_rest$= 37 s after the onset of the GRB. This …