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Title: MULTI-WAVELENGTH OBSERVATIONS OF SUPERNOVA 2011ei: TIME-DEPENDENT CLASSIFICATION OF TYPE IIb AND Ib SUPERNOVAE AND IMPLICATIONS FOR THEIR PROGENITORS

Abstract

We present X-ray, UV/optical, and radio observations of the stripped-envelope, core-collapse supernova (SN) 2011ei, one of the least luminous SNe IIb or Ib observed to date. Our observations begin with a discovery within {approx}1 day of explosion and span several months afterward. Early optical spectra exhibit broad, Type II-like hydrogen Balmer profiles that subside rapidly and are replaced by Type Ib-like He-rich features on a timescale of one week. High-cadence monitoring of this transition suggests absorption attributable to a high-velocity ({approx}> 12, 000 km s{sup -1}) H-rich shell, which is likely present in many Type Ib events. Radio observations imply a shock velocity of v Almost-Equal-To 0.13 c and a progenitor star average mass-loss rate of M-dot {approx}1.4 Multiplication-Sign 10{sup -5} M{sub sun} yr{sup -1} (assuming wind velocity v{sub w} = 10{sup 3} km s{sup -1}). This is consistent with independent constraints from deep X-ray observations with Swift-XRT and Chandra. Overall, the multi-wavelength properties of SN 2011ei are consistent with the explosion of a lower-mass (3-4 M{sub Sun }), compact (R{sub *} {approx}< 1 Multiplication-Sign 10{sup 11} cm), He-core star. The star retained a thin hydrogen envelope at the time of explosion, and was embedded in an inhomogeneous circumstellar windmore » suggestive of modest episodic mass loss. We conclude that SN 2011ei's rapid spectral metamorphosis is indicative of time-dependent classifications that bias estimates of the relative explosion rates for Type IIb and Ib objects, and that important information about a progenitor star's evolutionary state and mass loss immediately prior to SN explosion can be inferred from timely multi-wavelength observations.« less

Authors:
; ; ; ;  [1]; ;  [2]; ;  [3];  [4];  [5];  [6]; ; ; ; ;  [7]; ;  [8];  [9] more »; « less
  1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
  2. Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile)
  3. Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Lab, Hanover, NH 03755 (United States)
  4. Parkdale Observatory, 225 Warren Road, RDl Oxford, Canterbury 7495 (New Zealand)
  5. Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Strasse 1, D-85748 Garching (Germany)
  6. Kavli Institute for Theoretical Physics, Kohn Hall, University of California at Santa Barbara, Santa Barbara, CA 93106-4030 (United States)
  7. South African Astronomical Observatory, P.O. Box 9, Observatory 7935, Cape Town (South Africa)
  8. Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States)
  9. Southern African Large Telescope, P.O. Box 9, Observatory 7935, Cape Town (South Africa)
Publication Date:
OSTI Identifier:
22167386
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 767; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; HELIUM; HYDROGEN; LIMITING VALUES; MASS TRANSFER; METAMORPHOSIS; MONITORING; RADIOWAVE RADIATION; SPECTRA; STELLAR WINDS; SUPERNOVAE; TIME DEPENDENCE; ULTRAVIOLET RADIATION; VISIBLE RADIATION; WAVELENGTHS; X RADIATION

Citation Formats

Milisavljevic, Dan, Margutti, Raffaella, Soderberg, Alicia M., Chomiuk, Laura, Sanders, Nathan E., Pignata, Giuliano, Bufano, Filomena, Fesen, Robert A., Parrent, Jerod T., Parker, Stuart, Mazzali, Paolo, Pian, Elena, Pickering, Timothy, Buckley, David A. H., Crawford, Steven M., Gulbis, Amanda A. S., Hettlage, Christian, Hooper, Eric, Nordsieck, Kenneth H., O'Donoghue, Darragh, and others, and. MULTI-WAVELENGTH OBSERVATIONS OF SUPERNOVA 2011ei: TIME-DEPENDENT CLASSIFICATION OF TYPE IIb AND Ib SUPERNOVAE AND IMPLICATIONS FOR THEIR PROGENITORS. United States: N. p., 2013. Web. doi:10.1088/0004-637X/767/1/71.
Milisavljevic, Dan, Margutti, Raffaella, Soderberg, Alicia M., Chomiuk, Laura, Sanders, Nathan E., Pignata, Giuliano, Bufano, Filomena, Fesen, Robert A., Parrent, Jerod T., Parker, Stuart, Mazzali, Paolo, Pian, Elena, Pickering, Timothy, Buckley, David A. H., Crawford, Steven M., Gulbis, Amanda A. S., Hettlage, Christian, Hooper, Eric, Nordsieck, Kenneth H., O'Donoghue, Darragh, & others, and. MULTI-WAVELENGTH OBSERVATIONS OF SUPERNOVA 2011ei: TIME-DEPENDENT CLASSIFICATION OF TYPE IIb AND Ib SUPERNOVAE AND IMPLICATIONS FOR THEIR PROGENITORS. United States. https://doi.org/10.1088/0004-637X/767/1/71
Milisavljevic, Dan, Margutti, Raffaella, Soderberg, Alicia M., Chomiuk, Laura, Sanders, Nathan E., Pignata, Giuliano, Bufano, Filomena, Fesen, Robert A., Parrent, Jerod T., Parker, Stuart, Mazzali, Paolo, Pian, Elena, Pickering, Timothy, Buckley, David A. H., Crawford, Steven M., Gulbis, Amanda A. S., Hettlage, Christian, Hooper, Eric, Nordsieck, Kenneth H., O'Donoghue, Darragh, and others, and. 2013. "MULTI-WAVELENGTH OBSERVATIONS OF SUPERNOVA 2011ei: TIME-DEPENDENT CLASSIFICATION OF TYPE IIb AND Ib SUPERNOVAE AND IMPLICATIONS FOR THEIR PROGENITORS". United States. https://doi.org/10.1088/0004-637X/767/1/71.
@article{osti_22167386,
title = {MULTI-WAVELENGTH OBSERVATIONS OF SUPERNOVA 2011ei: TIME-DEPENDENT CLASSIFICATION OF TYPE IIb AND Ib SUPERNOVAE AND IMPLICATIONS FOR THEIR PROGENITORS},
author = {Milisavljevic, Dan and Margutti, Raffaella and Soderberg, Alicia M. and Chomiuk, Laura and Sanders, Nathan E. and Pignata, Giuliano and Bufano, Filomena and Fesen, Robert A. and Parrent, Jerod T. and Parker, Stuart and Mazzali, Paolo and Pian, Elena and Pickering, Timothy and Buckley, David A. H. and Crawford, Steven M. and Gulbis, Amanda A. S. and Hettlage, Christian and Hooper, Eric and Nordsieck, Kenneth H. and O'Donoghue, Darragh and others, and},
abstractNote = {We present X-ray, UV/optical, and radio observations of the stripped-envelope, core-collapse supernova (SN) 2011ei, one of the least luminous SNe IIb or Ib observed to date. Our observations begin with a discovery within {approx}1 day of explosion and span several months afterward. Early optical spectra exhibit broad, Type II-like hydrogen Balmer profiles that subside rapidly and are replaced by Type Ib-like He-rich features on a timescale of one week. High-cadence monitoring of this transition suggests absorption attributable to a high-velocity ({approx}> 12, 000 km s{sup -1}) H-rich shell, which is likely present in many Type Ib events. Radio observations imply a shock velocity of v Almost-Equal-To 0.13 c and a progenitor star average mass-loss rate of M-dot {approx}1.4 Multiplication-Sign 10{sup -5} M{sub sun} yr{sup -1} (assuming wind velocity v{sub w} = 10{sup 3} km s{sup -1}). This is consistent with independent constraints from deep X-ray observations with Swift-XRT and Chandra. Overall, the multi-wavelength properties of SN 2011ei are consistent with the explosion of a lower-mass (3-4 M{sub Sun }), compact (R{sub *} {approx}< 1 Multiplication-Sign 10{sup 11} cm), He-core star. The star retained a thin hydrogen envelope at the time of explosion, and was embedded in an inhomogeneous circumstellar wind suggestive of modest episodic mass loss. We conclude that SN 2011ei's rapid spectral metamorphosis is indicative of time-dependent classifications that bias estimates of the relative explosion rates for Type IIb and Ib objects, and that important information about a progenitor star's evolutionary state and mass loss immediately prior to SN explosion can be inferred from timely multi-wavelength observations.},
doi = {10.1088/0004-637X/767/1/71},
url = {https://www.osti.gov/biblio/22167386}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 767,
place = {United States},
year = {Wed Apr 10 00:00:00 EDT 2013},
month = {Wed Apr 10 00:00:00 EDT 2013}
}