Dust and the type II-plateau supernova 2004et (2009)
Kotak, Rubina, Meikle, Peter, Farrah, Duncan, Gerardy, Christopher, Foley, Ryan, Van Dyk, Schuyler, ...
We present mid-infrared (MIR) observations of the Type II-plateau supernova (SN) 2004et, obtained with the {\it Spitzer Space Telescope} between days 64 and 1406 past explosion. Late-time optical...
Modeling the X-ray emission of SN 1993J (2008)
Nymark, Tanja K., Chandra, Poonam, Fransson, Claes
We investigate the effects of radiative shocks on the observed X-ray emission from the Type II supernova SN 1993J. To this end, the X-ray emission is modeled as a result of the interaction between...
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...
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,...
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,...
Claes Fransson Cecilia Kozma (2007)
Stockholm Observatory Saltsjobaden, Claes Fransson, Cecilia Kozma
. Modeling of the late spectral and photometric evolution of SN 1987A is reviewed with special emphasis on abundances, the IRcatastrophe, mixing and photometry. Different methods for determining the...
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...
Infrared Integral Field Spectroscopy of SN 1987A (2007)
Kjaer, Karina, Leibundgut, Bruno, Fransson, Claes, Groeningsson, Per, Spyromilio, Jason, Kissler-Patig, Markus
SN 1987A in the Large Magellanic Cloud is close enough for a study of the very late time evolution of a supernova and its transition to a supernova remnant. Nearly two decades after explosion we are...
SN 1987A at the end of its second decade (2006)
Kjaer, Karina, Groeningsson, Per, Kotak, Rubina, Fransson, Claes, Leibundgut, Bruno
After nearly two decades at least five emission mechanisms can be found in SN 1987A. The ejecta continue to glow as a result of the radioactive decay of long-lived nuclei (mostly 44Ti), but is fading...
Spitzer measurements of atomic and molecular abundances in the Type IIP SN 2005af (2006)
Kotak, Rubina, Meikle, Peter, Pozzo, Monica, Van Dyk, Schuyler D., Farrah, Duncan, Fesen, Robert, ...
We present results based on Spitzer Space Telescope mid-infrared (3.6-30 micron) observations of the nearby IIP supernova 2005af. We report the first ever detection of the SiO molecule in a Type IIP...
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...
Coronal emission from the shocked circumstellar ring of SN 1987A (2006)
Groeningsson, Per, Fransson, Claes, Lundqvist, Peter, Nymark, Tanja, Lundqvist, Natalia, Chevalier, Roger, ...
High resolution spectra with UVES/VLT of SN 1987A from December 2000 until November 2005 show a number of high ionization lines from gas with velocities of roughly 350 km/s, emerging from the shocked...
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...
X-ray emission from radiative shocks in Type II supernovae (2005)
Nymark, Tanja K., Fransson, Claes, Kozma, Cecilia
The X-ray emission from the circumstellar interaction in Type II supernovae with a dense circumstellar medium is calculated. In Type IIL and Type IIn supernovae mass loss rates are generally high...
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...
Three-dimensional modeling of Type Ia supernovae - The power of late time spectra (2005)
Kozma, Cecilia, Fransson, Claes, Hillebrandt, Wolfgang, Travaglio, Claudia, Sollerman, Jesper, Reinecke, Martin, ...
Late time synthetic spectra of Type Ia supernovae, based on three-dimensional deflagration models, are presented. We mainly focus on one model,"c3_3d_256_10s", for which the hydrodynamics (Roepke...
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...
The late-time light curve of the Type Ia supernova 2000cx (2004)
Sollerman, Jesper, Lindahl, Jan, Kozma, Cecilia, Challis, Peter, Filippenko, Alexei V., Fransson, Claes, ...
We have conducted a systematic and comprehensive monitoring programme of the Type Ia supernova 2000cx at late phases using the VLT and HST. The VLT observations cover phases 360 to 480 days past...
Modeling the Radio and X-ray Emission of SN 1993J and SN 2002ap (2004)
Fransson, Claes, Bjornsson, Claes-Ingvar
Modeling of radio and X-ray observations of supernovae interacting with their circumstellar media are discussed, with special application to SN 1993J and SN 2002ap. We emphasize the importance of...
The galaxy population of intermediate-redshift clusters (2004)
Dahlen, Tomas, Fransson, Claes, Naslund, Magnus, Ostlin, Goran
Using photometric redshifts we determine the galaxy population of the clusters of galaxies Cl0016+16 at z=0.55, Cl1600+41 at z=0.54, Cl1601+42 at z=0.54 and MS1008-1224 at z=0.31. Comparing the...
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...
High-resolution optical studies of nearby Type Ia supernovae (2003)
Lundqvist, Peter, Mattila, Seppo, Sollerman, Jesper, Baron, E., Ehrenfreund, Pascale, Fransson, Claes, ...
Since April 2000, a program using the ESO/VLT/UVES to search for early circumstellar signatures from nearby supernovae has been conducted. Until now, two Type Ia supernovae have been observed, SNe...
Spectropolarimetry of SN 2001el in NGC 1448: Asphericity of a Normal Type Ia Supernova (2003)
Wang, Lifan, Baade, Dietrich, Hoeflich, Peter, Khokhlov, Alexei, Wheeler, J. Craig, Kasen, Daniel, ...
High-quality spectropolarimetry (range 417-860 nm; spectral resolution 1.27 nm and 0.265 nm/pixel) of the SN Ia 2001el were obtained with the ESO Very Large Telescope Melipal (+ FORS1) at 5 epochs....
Wang, Lifan, Baade, Dietrich, Hoeflich, Peter, Wheeler, J. Craig, Fransson, Claes, Lundqvist, Peter
High-quality spectropolarimetric data of SN 2002ap were obtained with the ESO Very Large Telescope Melipal (+ FORS1) at 3 epochs that correspond to -6, -2, and +1 days for a V maximum of 9 Feb 2002....
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...
Radioactivities and nucleosynthesis in SN 1987A (2001)
Fransson, Claes, Kozma, Cecilia
The nucleosynthesis and production of radioactive elements in SN 1987A are reviewed. Different methods for estimating the masses of 56Ni, 57Ni, and 44Ti are discussed, and we conclude that broad band...
The Galaxy Population of Cl1601+42 at z=0.54 (2001)
Dahlen, Tomas, Fransson, Claes, Naeslund, Magnus
Photometric redshifts are used to determine the rest frame luminosity function (LF) of both early-type and late-type galaxies to M_B ~ -17.6 for the cluster Cl1601+42 at z = 0.54. The total LF shows...
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...
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...
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....
Preliminary Spectral Analysis of the Type II Supernova 1999em (2000)
Baron, E., Branch, David, Hauschildt, Peter H., Filippenko, Alexei V., Kirshner, R. P., Challis, P. M., ...
We have calculated fast direct spectral model fits to two early-time spectra of the Type-II plateau SN 1999em, using the SYNOW synthetic spectrum code. The first is an extremely early blue optical...
Lentz, Eric J., Baron, E., Lundqvist, Peter, Branch, David, Hauschildt, Peter H., Fransson, Claes, ...
We present spectral analysis of early observations of the Type IIn supernova 1998S using the general non-local thermodynamic equilibrium atmosphere code \tt PHOENIX}. We model both the underlying...
HST Spectroscopy of Spot 1 on the Circumstellar Ring of SN 1987A (2000)
Michael, Eli, McCray, Richard, Pun, C. S. J., Garnavich, Peter, Challis, Peter, Kirshner, Robert P., ...
We present ultraviolet and optical spectra of the first bright spot (PA = 29 degrees) on Supernova 1987A's equatorial circumstellar ring taken with the Space Telescope Imaging Spectrograph. We...
SN 1998bw at late phases (2000)
Sollerman, Jesper, Kozma, Cecilia, Fransson, Claes, Leibundgut, Bruno, Lundqvist, Peter, Ryde, Felix, ...
We present observations of the peculiar supernova SN 1998bw, which was probably associated with GRB 980425. The photometric and spectroscopic evolution is monitored up to 500 days past explosion. We...
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...
Rates and redshift distribution of high-z supernovae (1999)
Dahlen, Tomas, Fransson, Claes
Using observed star formation rates at redshifts up to z ~ 5, we calculate cosmic supernova rates for core collapse and Type Ia supernovae. Together with supernova statistics and detailed light...
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...
High z supernovae with the NGST (1998)
Dahlen, Tomas, Fransson, Claes
We use different assumptions for the combination of dust extinction and star formation up to redshifts z >= 5, as well as detailed modeling of supernova properties, to estimate the number of...
Radio Emission and Particle Acceleration in SN 1993J (1998)
Fransson, Claes, Björnsson, Claes-Ingvar
The radio light curves of SN 1993J are found to be well fit by a synchrotron spectrum, suppressed by external free-free absorption and synchrotron self-absorption. A standard r^-2 circumstellar...
Late Spectral Evolution of SN 1987A: I. Temperature and Ionization (1997)
Kozma, Cecilia, Fransson, Claes
The temperature and ionization of SN 1987A is modeled between 200 and 2000 days in its nebular phase, using a time-dependent model. We include all important elements, as well as the primary...
Late Spectral Evolution of SN 1987A: II. Line Emission (1997)
Kozma, Cecilia, Fransson, Claes
Using the temperature and ionization calculated in our previous paper, we model the spectral evolution of SN 1987A. The IR-catastrophe is seen in the metal lines as a transition from thermal to...
Hubble Space Telescope Spectroscopic Observations of the Ejecta of SN 1987A at 2000 Days (1996)
Wang, Lifan, Wheeler, J. Craig, Kirshner, Robert P., Challis, Peter M., Filippenko, Alexei V., Fransson, Claes, ...
We have used the Faint Object Spectrograph on the Hubble Space Telescope to observe the spectra of SN 1987A over the wavelength range 2000 -- 8000\ \AA\ on dates 1862 and 2210 days after the...
Fysikaliska processer I unga supernovor /--Claes Fransson. (1983)
Contient 3 tirés à part : Fransson (Claes). - Line profiles from supernovae. - 1982. - Comptonization and UV emission lines from type I supernovae. - 1982. - Physical conditions in the UV line...