Philipp Podsiadlowski: Publications

Hunting for the progenitor of SN 1006: High resolution spectroscopic search with the FLAMES instrument

ArXiv 1207.4481 (2012)

Authors:

Wolfgang E Kerzendorf, Brian P Schmidt, John B Laird, Philipp Podsiadlowski, Michael S Bessell

Abstract:

Type Ia supernovae play a significant role in the evolution of the Universe and have a wide range of applications. It is widely believed that these events are the thermonuclear explosions of carbon-oxygen white dwarfs close to the Chandrasekhar mass (1.38 M\odot). However, CO white dwarfs are born with masses much below the Chandrasekhar limit and thus require mass accretion to become Type Ia supernovae. There are two main scenarios for accretion. First, the merger of two white dwarfs and, second, a stable mass accretion from a companion star. According to predictions, this companion star (also referred to as donor star) survives the explosion and thus should be visible in the center of Type Ia remnants. In this paper we scrutinize the central stars (79 in total) of the SN 1006 remnant to search for the surviving donor star as predicted by this scenario. We find no star consistent with the traditional accretion scenario in SN1006.

PTF11kx: A Type-Ia Supernova with a Symbiotic Nova Progenitor

ArXiv 1207.1306 (2012)

Authors:

B Dilday, DA Howell, SB Cenko, JM Silverman, PE Nugent, M Sullivan, S Ben-Ami, L Bildsten, M Bolte, M Endl, AV Filippenko, O Gnat, A Horesh, E Hsiao, MM Kasliwal, D Kirkman, K Maguire, GW Marcy, K Moore, Y Pan, JT Parrent, P Podsiadlowski, RM Quimby, A Sternberg, N Suzuki, DR Tytler, D Xu, JS Bloom, A Gal-Yam, IM Hook, SR Kulkarni, NM Law, EO Ofek, D Polishook, D Poznanski

Abstract:

There is a consensus that Type-Ia supernovae (SNe Ia) arise from the thermonuclear explosion of white dwarf stars that accrete matter from a binary companion. However, direct observation of SN Ia progenitors is lacking, and the precise nature of the binary companion remains uncertain. A temporal series of high-resolution optical spectra of the SN Ia PTF 11kx reveals a complex circumstellar environment that provides an unprecedentedly detailed view of the progenitor system. Multiple shells of circumsteller are detected and the SN ejecta are seen to interact with circumstellar material (CSM) starting 59 days after the explosion. These features are best described by a symbiotic nova progenitor, similar to RS Ophiuchi.

Hubble Space Telescope studies of low-redshift Type Ia supernovae: Evolution with redshift and ultraviolet spectral trends

ArXiv 1205.704 (2012)

Authors:

K Maguire, M Sullivan, RS Ellis, PE Nugent, DA Howell, A Gal-Yam, J Cooke, P Mazzali, Y-C Pan, B Dilday, RC Thomas, I Arcavi, S Ben-Ami, D Bersier, FB Bianco, BJ Fulton, I Hook, A Horesh, E Hsiao, PA James, P Podsiadlowski, ES Walker, O Yaron, MM Kasliwal, RR Laher, NM Law, EO Ofek, D Poznanski, J Surace

Abstract:

We present an analysis of the maximum light, near ultraviolet (NUV; 2900-5500 A) spectra of 32 low redshift (0.001

A Jet Break in the X-ray Light Curve of Short GRB 111020A: Implications for Energetics and Rates

ArXiv 1204.5475 (2012)

Authors:

Wen-fai Fong, Edo Berger, Raffaella Margutti, B Ashley Zauderer, Eleonora Troja, Ian Czekala, Ryan Chornock, Neil Gehrels, Takanori Sakamoto, Derek B Fox, Philipp Podsiadlowski

Abstract:

We present broad-band observations of the afterglow and environment of the short GRB 111020A. An extensive X-ray light curve from Swift/XRT, XMM-Newton and Chandra, spanning ~100 seconds to 10 days after the burst, reveals a significant break at t~2 days with pre- and post-break decline rates of alphaX,1 ~ -0.78 and alphaX,2<-1.7, respectively. Interpreted as a jet break, we infer a collimated outflow with an opening angle of ~3-8 degrees. The resulting beaming-corrected gamma-ray (10-1000 keV band) and blastwave kinetic energies are (2-3)e48 erg and (0.3-2)e49 erg, respectively, with the range depending on the unknown redshift of the burst. We report a radio afterglow limit of <39 microJy (3-sigma) from EVLA observations which, along with our finding that vc24.4 mag at 18 hours after the burst, and reveal a potential host galaxy with i~24.3 mag. The sub-arcsecond localization from Chandra provides a precise offset of 0.80"+/-0.11" (1-sigma) from this galaxy corresponding to an offset of 5-7 kpc for z=0.5-1.5. We find a high excess neutral Hydrogen column density of (7.5+/-2.0)e21 cm^(-2) (z=0). Our observations demonstrate that a growing fraction of short GRBs are collimated which may lead to a true event rate of >100-1000 Gpc^(-3) yr^(-1), in good agreement with the NS-NS merger rate of ~200-3000 Gpc^(-3) yr^(-1). This consistency is promising for coincident short GRB-gravitational wave searches in the forthcoming era of Advanced LIGO/VIRGO.

Early radio and X-ray observations of the youngest nearby Type Ia supernova PTF11kly (SN2011fe)

Astrophysical Journal 746:1 (2012)

Authors:

A Horesh, SR Kulkarni, DB Fox, J Carpenter, MM Kasliwal, EO Ofek, R Quimby, A Gal-Yam, SB Cenko, AG De Bruyn, A Kamble, RAMJ Wijers, AJ Van Der Horst, C Kouveliotou, P Podsiadlowski, M Sullivan, K Maguire, DA Howell, PE Nugent, N Gehrels, NM Law, D Poznanski, M Shara

Abstract:

On 2011 August 24 (UT) the Palomar Transient Factory (PTF) discovered PTF11kly (SN 2011fe), the youngest and most nearby Type Ia supernova (SN Ia) in decades. We followed this event up in the radio (centimeter and millimeter bands) and X-ray bands, starting about a day after the estimated explosion time. We present our analysis of the radio and X-ray observations, yielding the tightest constraints yet placed on the pre-explosion mass-loss rate from the progenitor system of this supernova. We find a robust limit of from sensitive X-ray non-detections, as well as a similar limit from radio data, which depends, however, on assumptions about microphysical parameters. We discuss our results in the context of single-degenerate models for SNe Ia and find that our observations modestly disfavor symbiotic progenitor models involving a red giant donor, but cannot constrain systems accreting from main-sequence or sub-giant stars, including the popular supersoft channel. In view of the proximity of PTF11kly and the sensitivity of our prompt observations, we would have to wait for a long time (a decade or longer) in order to more meaningfully probe the circumstellar matter of SNe Ia. © 2012. The American Astronomical Society. All rights reserved.

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