Massive stars exploding in a He-rich circumstellar medium - V. Observations of the slow-evolving SN Ibn OGLE-2012-SN-006

We present optical observations of the peculiar Type Ibn supernova (SN Ibn) OGLE-2012-SN- 006, discovered and monitored by the Optical Gravitational Lensing Experiment-IV survey, and spectroscopically followed by Public ESO Spectroscopic Survey of Transient Objects (PESSTO) at late phases. Stringent...

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Autor principal: Bersten, Melina Cecilia
Formato: Articulo
Lenguaje:Inglés
Publicado: 2015
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/85986
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id I19-R120-10915-85986
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
Supernovae: general
Supernovae: individual: OGLE-2012-SN-006
Supernovae: individual: SN 2006jc
Supernovae: individual: SN 2010al
spellingShingle Ciencias Astronómicas
Supernovae: general
Supernovae: individual: OGLE-2012-SN-006
Supernovae: individual: SN 2006jc
Supernovae: individual: SN 2010al
Bersten, Melina Cecilia
Massive stars exploding in a He-rich circumstellar medium - V. Observations of the slow-evolving SN Ibn OGLE-2012-SN-006
topic_facet Ciencias Astronómicas
Supernovae: general
Supernovae: individual: OGLE-2012-SN-006
Supernovae: individual: SN 2006jc
Supernovae: individual: SN 2010al
description We present optical observations of the peculiar Type Ibn supernova (SN Ibn) OGLE-2012-SN- 006, discovered and monitored by the Optical Gravitational Lensing Experiment-IV survey, and spectroscopically followed by Public ESO Spectroscopic Survey of Transient Objects (PESSTO) at late phases. Stringent pre-discovery limits constrain the explosion epoch with fair precision to JD = 245 6203.8 ± 4.0. The rise time to the I-band light-curve maximum is about two weeks. The object reaches the peak absolute magnitude M<SUB>I</SUB> = -19.65 ± 0.19 on JD = 245 6218.1 ± 1.8. After maximum, the light curve declines for about 25 d with a rate of 4 mag (100 d)<SUP>-1</SUP>. The symmetric I-band peak resembles that of canonical Type Ib/c supernovae (SNe), whereas SNe Ibn usually exhibit asymmetric and narrower early-time light curves. Since 25 d past maximum, the light curve flattens with a decline rate slower than that of the <SUP>56</SUP>Co-<SUP>56</SUP>Fe decay, although at very late phases it steepens to approach that rate. However, other observables suggest that the match with the <SUP>56</SUP>Co decay rate is a mere coincidence, and the radioactive decay is not the main mechanism powering the light curve of OGLE-2012-SN- 006. An early-time spectrum is dominated by a blue continuum, with only a marginal evidence for the presence of He I lines marking this SN type. This spectrum shows broad absorptions bluewards than 5000 Å, likely OII lines, which are similar to spectral features observed in superluminous SNe at early epochs. The object has been spectroscopically monitored by PESSTO from 90 to 180 d after peak, and these spectra show the typical features observed in a number of SN 2006jc-like events, including a blue spectral energy distribution and prominent and narrow (υ<SUB>FWHM</SUB> ≈ 1900 km s<SUP>-1</SUP>) HeI emission lines. This suggests that the ejecta are interacting with He-rich circumstellar material. The detection of broad (10<SUP>4</SUP> km s<SUP>-1</SUP>) OI and Ca II features likely produced in the SN ejecta (including the [OI] λλ6300,6364 doublet in the latest spectra) lends support to the interpretation of OGLE-2012-SN-006 as a core-collapse event.
format Articulo
Articulo
author Bersten, Melina Cecilia
author_facet Bersten, Melina Cecilia
author_sort Bersten, Melina Cecilia
title Massive stars exploding in a He-rich circumstellar medium - V. Observations of the slow-evolving SN Ibn OGLE-2012-SN-006
title_short Massive stars exploding in a He-rich circumstellar medium - V. Observations of the slow-evolving SN Ibn OGLE-2012-SN-006
title_full Massive stars exploding in a He-rich circumstellar medium - V. Observations of the slow-evolving SN Ibn OGLE-2012-SN-006
title_fullStr Massive stars exploding in a He-rich circumstellar medium - V. Observations of the slow-evolving SN Ibn OGLE-2012-SN-006
title_full_unstemmed Massive stars exploding in a He-rich circumstellar medium - V. Observations of the slow-evolving SN Ibn OGLE-2012-SN-006
title_sort massive stars exploding in a he-rich circumstellar medium - v. observations of the slow-evolving sn ibn ogle-2012-sn-006
publishDate 2015
url http://sedici.unlp.edu.ar/handle/10915/85986
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