Type IIB Supernovae with Compact and Extended Progenitors (2009)
Chevalier, Roger A., Soderberg, Alicia M.
The classic example of a Type IIb supernova is SN 1993J, which had a cool extended progenitor surrounded by a dense wind. There is evidence for another category of Type IIb supernova which has a more...
Eleven Years of Radio Monitoring of the type IIn Supernova SN 1995N (2009)
Chandra, Poonam, Stockdale, Christopher J., Chevalier, Roger A., Van Dyk, Schuyler D., Ray, Alak, Kelley, Matthew T., ...
We present radio observations of the optically bright Type IIn supernova SN 1995N. We observed the SN at radio wavelengths with the Very Large Array for 11 years. We also observed it at low radio...
Groeningsson, Per, Fransson, Claes, Leibundgut, Bruno, Lundqvist, Peter, Challis, Peter, Chevalier, Roger A., ...
We present seven epochs between October 1999 and November 2007 of high resolution VLT/UVES echelle spectra of the ejecta-ring collision of SN 1987A. The fluxes of most of the narrow lines from the...
Eleven years of radio monitoring of the Type IIn supernova SN 1995N (2008)
Chandra, Poonam, Stockdale, Christopher J., Chevalier, Roger A., Van Dyk, Schuyler D., Ray, Alak, Kelley, Matthew T., ...
We present radio observations of the optically bright Type IIn supernova SN 1995N. We observed the SN at radio wavelengths with the Very Large Array (VLA) for 11 years. We also observed it at low...
A comprehensive study of GRB 070125, a most energetic gamma-ray burst (2008)
Chandra, Poonam, Cenko, S. Bradley, Frail, Dale A., Chevalier, Roger A., Macquart, Jean-Pierre, Kulkarni, Shri R., ...
We present a comprehensive multiwavelength analysis of the bright, long-duration gamma-ray burst GRB 070125, comprised of observations in gamma-ray, X-ray, optical, millimeter, and centimeter wave...
A comprehensive study of GRB 070125, a most energetic gamma-ray burst (2008)
Chandra, Poonam, Cenko, S. Bradley, Frail, Dale A., Chevalier, Roger A., Macquart, Jean-Pierre, Kulkarni, Shri R., ...
We present a comprehensive multiwavelength analysis of the bright, long-duration gamma-ray burst GRB 070125, comprised of observations in gamma-ray, X-ray, optical, millimeter, and centimeter wave...
Near-Infrared Photometry of the Type IIn SN 2005ip: The Case for Dust Condensation (2008)
Fox, Ori, Skrutskie, Michael F., Chevalier, Roger A., Kanneganti, Srikrishna, Park, Chan, Wilson, John, ...
Near-infrared photometric observations of the Type IIn SN 2005ip in NGC 2906 reveal large fluxes (>1.3 mJy) in the K_s-band over more than 900 days. While warm dust can explain the late-time K_s-band...
Shock Breakout Emission from a Type Ib/c Supernova: XRF 080109/SN 2008D (2008)
Chevalier, Roger A., Fransson, Claes
The X-ray flash 080109, associated with SN 2008D, can be attributed to the shock breakout emission from a normal Type Ib/c supernova. If the observed emission is interpreted as blackbody emission,...
Multiwaveband analysis of brightest GRB070125 (2008)
Chandra, Poonam, Cenko, S. Bradley, Frail, Dale A., Chevalier, Roger A., Macquart, Jean-Pierre, Kulkarni, Shri R., ...
We present a comprehensive multiwavelength analysis of the bright, long duration gamma-ray burst GRB 070125, comprised of observations in gamma-ray, X-ray, optical, millimeter and centimeter...
Late-Time HST Photometry of SN 1994I: Hints of Positron Annihilation Energy Deposition (2008)
Clocchiatti, Alejandro, Wheeler, J. Craig, Kirshner, Robert P., Branch, David, Challis, Peter, Chevalier, Roger A., ...
We present multicolor Hubble Space Telescope (HST) WFPC2 broadband observations of the Type Ic SN 1994I obtained approximately 280 days after maximum light. We measure the brightness of the SN and,...
Direct Analysis of Spectra of the Type Ic Supernova 1994I (2007)
Jennifer Millard, David Branch, E. Baron, Adam Fisher, A. V. Filippenko, R. P. Kirshner, ...
Synthetic spectra generated by the parameterized supernova synthetic-- spectrum code SYNOW are compared to observed photospheric--phase spectra of the Type Ic supernova 1994I. The observed optical...
What Gamma-Ray Bursts Explode Into (2007)
The association of long gamma-ray bursts (GRBs) with Type Ib/c supernovae implies that they explode into the winds of their Wolf-Rayet progenitor stars. Although the evolution of some GRB afterglows...
Groeningsson, Per, Fransson, Claes, Lundqvist, Peter, Lundqvist, Natalia, Leibundgut, Bruno, Spyromilio, Jason, ...
We discuss high resolution VLT/UVES observations (FWHM ~ 6 km/s) from October 2002 (day ~5700 past explosion) of the shock interaction of SN 1987A and its circumstellar ring. A nebular analysis of...
Optical Signatures of Circumstellar Interaction in Type IIP Supernovae (2007)
Chugai, Nikolai N., Chevalier, Roger A., Utrobin, Victor P.
We propose new diagnostics for circumstellar interaction in Type IIP supernovae by the detection of high velocity (HV) absorption features in Halpha and He I 10830 A lines during the photospheric...
Moderate Asphericity of the SN 2002ic Circumstellar Envelope (2006)
Chugai, Nikolai N., Chevalier, Roger A.
The polarization of SN 2002ic interacting with a dense circumstellar envelope is calculated in the context of the asymmetric version of a previously proposed spherical interaction model. The...
From progenitor to afterlife (2006)
The sequence of massive star supernova types IIP (plateau light curve), IIL (linear light curve), IIb, IIn (narrow line), Ib, and Ic roughly represents a sequence of increasing mass loss during the...
Circumstellar Emission from Type Ib and Ic Supernovae (2006)
Chevalier, Roger A., Fransson, Claes
The presumed Wolf-Rayet star progenitors of Type Ib/c supernovae have fast, low density winds and the shock waves generated by the supernova interaction with the wind are not expected to be radiative...
Evolution of the Reverse Shock Emission from SNR 1987A (2006)
Heng, Kevin, McCray, Richard, Zhekov, Svetozar A., Challis, Peter M., Chevalier, Roger A., Crotts, Arlin P. S., ...
We present new (2004 July) G750L and G140L Space Telescope Imaging Spectrograph (STIS) data of the H-alpha and Ly-alpha emission from supernova remnant (SNR) 1987A. With the aid of earlier data, from...
Late Emission from the Type Ib/c SN 2001em: Overtaking the Hydrogen Envelope (2005)
Chugai, Nikolai N., Chevalier, Roger A.
The Type Ib/c supernova SN 2001em was observed to have strong radio, X-ray, and Halpha emission at an age of about 2.5 yr. Although the radio and X-ray emission have been attributed to an off-axis...
Radio and X-Ray Emission as Probes of Type IIP Supernovae and Red Supergiant Mass Loss (2005)
Chevalier, Roger A., Fransson, Claes, Nymark, Tanja K.
Type IIP (plateau) supernovae are thought to come from stars with initial mass about 8-25 solar masses that end their lives as red supergiants. The expected stellar end points can be found from...
Fransson, Claes, Challis, Peter M., Chevalier, Roger A., Filippenko, Alexei V., Kirshner, Robert P., Kozma, Cecilia, ...
Ground-based and Hubble Space Telescope observations are presented for SN 1993J and SN 1998S. SN 1998S shows strong, relatively narrow circumstellar emission lines of N III-V and C III-IV, as well as...
Young core collapse supernova remnants and their supernovae (2004)
Massive star supernovae can be divided into four categories depending on the amount of mass loss from the progenitor star and the star's radius: red supergiant stars with most of the H envelope...
The Diversity of Gamma-Ray Bursts and the Surroundings of Massive Stars (2003)
Chevalier, Roger A., Li, Zhi-Yun, Fransson, Claes
The finding of a Type Ic supernova connected with GRB 030329 showed a massive star origin for this burst, supporting evidence for this association in previous bursts with lightcurve bumps at the...
Pulsar Wind Nebulae and Their Supernovae (2003)
Young supernova remnants that contain pulsar wind nebulae provide diagnostics for both the inner part of the supernova and the interaction with the surrounding medium, providing an opportunity to...
Supernova Remnant and Pulsar Wind Nebula Interactions (2003)
I review several topics in the structure of supernova remnants. Hydrodynamic instabilities in young remnants may give rise to the cellular structure that is sometimes observed, although structure in...
The Surroundings of Gamma-Ray Bursts: Constraints on Progenitors (2003)
The association of a supernova with a gamma-ray burst (GRB 030329) implies a massive star progenitor, which is expected to have an environment formed by pre-burst stellar winds. Although some sources...
Cassiopeia A and its Clumpy Presupernova Wind (2003)
Chevalier, Roger A., Oishi, Jeffrey
The observed shock wave positions and expansion in Cas A can be interpreted in a model of supernova interaction with a freely expanding stellar wind with a mass loss rate of ~3e-5 Msun/yr for a wind...
Wind-Interaction Models for the Early Afterglows of Gamma-Ray Bursts: The Case of GRB 021004 (2003)
Li, Zhi-Yun, Chevalier, Roger A.
Wind-interaction models for gamma-ray burst afterglows predict that the optical emission from the reverse shock drops below that from the forward shock within 100s of seconds of the burst. The...
Circumstellar Interaction Around Supernovae (2003)
Circumstellar interaction has been observed around all types of massive star supernovae, especially at radio and X-ray wavelengths. The interaction shells in Type Ib/c supernovae appear to be moving...
Pulsar Wind Nebulae: Theoretical Aspects and Observational Constraints (2003)
Of the known pulsar wind nebulae, 8 are good candidates for being in the early stage of evolution where the wind nebula is interacting with the freely expanding supernova ejecta. Several of these...
Pun, Chun S. J., Michael, Eli, Zhekov, Svetozar A., McCray, Richard, Garnavich, Peter M., Challis, Peter M., ...
We report and interpret HST/STIS long-slit observations of the optical and ultraviolet (1150 - 10270 Angstrom) emission-line spectra of the rapidly brightening Spot 1 on the equatorial ring of SN...
Interactions between Pulsars, Pulsar Nebulae and Supernova Remnants (2002)
The Crab Nebula is likely to be expanding into freely expanding supernova ejecta, although the energy in the ejecta may be less than is typical for a Type II supernova. Pulsar nebulae much younger...
Bullets in a Core Collapse Supernova Remnant: The Vela Remnant (2001)
Wang, Chih-Yueh, Chevalier, Roger A.
We use two-dimensional hydrodynamical simulations to investigate the properties of dense ejecta clumps (bullets) in a core collapse supernova remnant, motivated by the observation of protrusions...
Supernova Interaction with a Circumstellar Medium (2001)
Chevalier, Roger A., Fransson, Claes
The explosion of a core collapse supernova drives a powerful shock front into the wind from the progenitor star. A layer of shocked circumstellar gas and ejecta develops that is subject to...
Interaction Models for GRB Afterglows (2001)
Li, Zhi-Yun, Chevalier, Roger A.
We review interaction models for GRB afterglows, with an eye on constraining the nature of their progenitors and the geometry of explosion. Evidence is presented for two types of progenitors. The...
Hubble Space Telescope WFPC-2 Imaging of Cassiopeia A (2001)
Fesen, Robert A., Morse, Jon A., Chevalier, Roger A., Borkowski, Kazimierz J., Gerardy, Christopher L., Lawrence, Stephen S., ...
The young SNR Cassiopeia A was imaged with WFPC-2 through four filters selected to capture the complete velocity range of the remnant's main shell in several important emission lines. Primary lines...
Fransson, Claes, Chevalier, Roger A., Filippenko, Alexei V., Leibundgut, Bruno, Barth, Aaron J., Fesen, Robert A., ...
Optical and ultraviolet observations of the Type IIn supernova 1995N at epochs between 321 and 1799 days after the explosion show three distinct velocity components. The narrow lines come from...
Interacting Stellar Wind and Photoionization Models of the SN 1987A Remnant (2001)
Link, Robert, Rosenberg, Duane L., Chevalier, Roger A.
We are investigating the SN 1987A remnant by modeling the circumstellar environment of the progenitor star. Interacting stellar winds models have been reasonably successful at reproducing the gross...
The Nature of the Compact Supernova Remnants in Starburst Galaxies (2001)
Chevalier, Roger A., Fransson, Claes
Radio observations of starburst regions in galaxies have revealed groups of compact nonthermal sources that may be radiative supernova remnants expanding in the interclump medium of molecular clouds....
Pulsar Wind Nebulae in Evolved Supernova Remnants (2001)
Blondin, John M., Chevalier, Roger A., Frierson, Dargan M.
For pulsars similar to the one in the Crab Nebula, most of the energy input to the surrounding wind nebula occurs on a timescale of less than 1000 years; during this time, the nebula expands into...
Supernovae in Molecular Clouds (2001)
Supernovae are expected to occur near the molecular material in which the massive progenitor star was born, except in cases where the photoionizing radiation and winds from the progenitor star and...
Theoretical Implications of the Gamma-Ray Burst - Supernova Connection (2001)
Although observations of circumstellar shock interactions around supernovae are generally consistent with a 1/r**2 density profile wind surrounding the progenitor star, this is not true for GRB...
Wind Interaction Models for the Afterglows of GRB 991208 and GRB 000301C (2000)
Li, Zhi-Yun, Chevalier, Roger A.
The simplest model of the afterglows of the gamma-ray bursts (GRBs) envisions a spherical blast wave with a power-law distribution of electron energy above some cutoff running into a constant density...
The X-ray Remnant of SN1987A (2000)
Burrows, David N., Michael, Eli, Hwang, Una, McCray, Richard, Chevalier, Roger A., Petre, Robert, ...
We present high resolution Chandra observations of the remnant of SN1987A in the Large Magellanic Cloud. The high angular resolution of the Chandra X-ray Observatory (CXO) permits us to resolve the...
Young Circumstellar Disks Near Evolved Massive Stars and Supernovae (2000)
There is increasing evidence that low mass stars with circumstellar disks can be born close to massive stars, in some cases within tenths of a pc. If the disks have lifetimes greater than those of...
Implications of the X-Ray Properties of Pulsar Nebulae (2000)
A plausible model for the Crab Nebula is one in which a particle dominated, highly relativistic wind from the pulsar passes through a shock front in which the particles attain a power law energy...
Instabilities and Clumping in Type Ia Supernova Remnants (2000)
Wang, Chih-Yueh, Chevalier, Roger A.
We present two-dimensional high-resolution hydrodynamical simulations in spherical polar coordinates of a Type Ia supernova interacting with a constant density interstellar medium. The ejecta are...
Observations of the Crab Nebula and its pulsar in the far-ultraviolet and in the optical (2000)
Sollerman, Jesper, Lundqvist, Peter, Lindler, Don, Chevalier, Roger A., Fransson, Claes, Gull, Theodore R., ...
We present HST/STIS far-UV observations of the Crab nebula and its pulsar. Broad, blueshifted absorption arising in the nebula is seen in C IV 1550, reaching about 2500 km/s. This can be interpreted...
Supernova Remnants in the Fossil Starburst in M82 (1999)
De Grijs, Richard, O'Connell, Robert W., Becker, George D., Chevalier, Roger A., Gallagher III, John S.
We report the discovery of ten compact H-alpha-bright sources in the post-starburst region northeast of the center of M82, ``M82 B.'' These objects have H alpha luminosities and sizes consistent with...
Wind Interaction Models for Gamma-Ray Burst Afterglows: The Case for Two Types of Progenitors (1999)
Chevalier, Roger A., Li, Zhi-Yun
Beginning with the $\gamma$-ray bursts GRB 970228 and GRB 970508, a standard model for the interpretation of GRB afterglows emerged involving synchrotron emission from a constant energy blast wave...
Radio Supernova SN 1998bw and Its Relation to GRB 980425 (1999)
Li, Zhi-Yun, Chevalier, Roger A.
SN 1998bw is an unusual Type Ic supernova that may be associated with the $\gamma$-ray burst GRB 980425. We use a synchrotron self-absorption model for its radio emission to deduce that the...
Late-Time Optical and UV Spectra of SN 1979C and SN 1980K (1998)
Fesen, Robert A., Gerardy, Christopher L., Filippenko, Alexei V., Matheson, Thomas, Chevalier, Roger A., Kirshner, Robert P., ...
A low-dispersion Keck I spectrum of SN 1980K taken in August 1995 (t = 14.8 yr after explosion) and a November 1997 MDM spectrum (t = 17.0 yr) show broad 5500 km s^{-1} emission lines of H\alpha, [O...
Hubble Space Telescope WFPC2 Imaging of SN 1979C and Its Environment (1998)
Van Dyk, Schuyler D., Peng, Chien Y., Barth, Aaron J., Filippenko, Alexei V., Chevalier, Roger A., Fesen, Robert A., ...
The locations of supernovae in the local stellar and gaseous environment in galaxies contain important clues to their progenitor stars. As part of a program to study the environments of supernovae...
Supernova Remnants in Molecular Clouds (1998)
Molecular clouds are known to be clumpy, with dense molecular clumps occupying only a few percent of the volume. A supernova remnant then evolves primarily in the interclump medium, and becomes...
Recent X-Ray Observations of SN1986J with ASCA and ROSAT (1997)
Houck, John C., Bregman, Joel N., Chevalier, Roger A., Tomisaka, Kohji
We present ASCA and ROSAT observations of SN 1986J covering the period 1991 August to 1996 January. From observations with the ROSAT HRI and PSPC, we find that the 0.5-2.5 keV flux decreased...
Axisymmetric circumstellar interaction in supernovae (1996)
Blondin, John M., Lundqvist, P., Chevalier, Roger A.
Multiwavelength observations of Type II supernovae have shown evidence for the interaction of supernovae with the dense slow winds from the red supergiant progenitor stars. Observations of planetary...