Change search
ReferencesLink to record
Permanent link

Direct link
Early-time light curves of Type Ib/c supernovae from the SDSS-II Supernova Survey
Stockholm University, Faculty of Science, Department of Astronomy.
Stockholm University, Faculty of Science, Department of Astronomy.
Show others and affiliations
2015 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 574, A60Article in journal (Refereed) Published
Abstract [en]

Context. Type Ib/c supernovae (SNe Ib/c) have been investigated in several single-object studies; however, there is still a paucity of works concerning larger, homogeneous samples of these hydrogen-poor transients, in particular regarding the premaximum phase of their light curves.

Aims. In this paper we present and analyze the early-time optical light curves (LCs, ugriz) of 20 SNe Ib/c from the Sloan Digital Sky Survey (SDSS) SN survey II, aiming to study their observational and physical properties, as well as to derive their progenitor parameters.

Methods. High-cadence, multiband LCs are fitted with a functional model and the best-fit parameters are compared among the SN types. Bolometric LCs (BLCs) are constructed for the entire sample. We also computed the black-body (BB) temperature (TBB) and photospheric radius (Rph) evolution for each SN via BB fits on the spectral energy distributions. In addition, the bolometric properties are compared to both hydrodynamical and analytical model expectations.

Results. Complementing our sample with literature data, we find that SNe Ic and Ic-BL (broad-line) have shorter rise times than those of SNe Ib and IIb. The decline rate parameter, Δm15, is similar among the different subtypes. SNe Ic appear brighter and bluer than SNe Ib, but this difference vanishes if we consider host galaxy extinction corrections based on colors. Templates for SN Ib/c LCs are presented. Our SNe have typical TBB of ~10 000 K at the peak and Rph of ~1015 cm. Analysis of the BLCs of SNe Ib and Ic gives typical ejecta masses Mej≈ 3.6−5.7  M, energies EK≈ 1.5−1.7×1051 erg, and M(56Ni) ≈ 0.3  M. Higher values for EK and M(56Ni) are estimated for SNe Ic-BL (Mej≈ 5.4  MEK≈ 10.7×1051 erg, M(56Ni) ≈ 1.1  M). For the majority of SNe Ic and Ic-BL, we can put strong limits (<2−4 days) on the duration of the expected early-time plateau. Less stringent limits can be placed on the duration of the plateau for the sample of SNe Ib. In the single case of SN Ib 2006lc, a >5.9 days plateau seems to be detected. The rising part of the BLCs is reproduced by power laws with index <2. For two events (SN 2005hm and SN 2007qx), we find signatures of a possible shock break-out cooling tail.

Conclusions. Based on the limits for the plateau length and on the slow rise of the BLCs, we find that in most of our SNe Ic and Ic-BL the 56Ni is mixed out to the outer layers, suggesting that SN Ic progenitors are de facto helium poor. The derived progenitor parameters (56Ni, EKMej) are consistent with previous works.

Place, publisher, year, edition, pages
2015. Vol. 574, A60
Keyword [en]
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Solar and Stellar Astrophysics
National Category
Astronomy, Astrophysics and Cosmology
URN: urn:nbn:se:su:diva-108294DOI: 10.1051/0004-6361/201423915ISI: 000349467000060OAI: diva2:756624
Available from: 2014-10-17 Created: 2014-10-17 Last updated: 2015-04-09Bibliographically approved
In thesis
1. Observations of rare supernovae and their environments
Open this publication in new window or tab >>Observations of rare supernovae and their environments
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Supernovae (SNe) are the final stage in the life of massive stars. Their explosion unbinds the progenitor star revealing its inner layers. The SN ejecta interact with the circumstellar material (CSM), providing further information on the progenitor star.

In this work we present the study of rare SN subtypes, aiming to investigate their observational and physical properties and those of their progenitor stars.These studies include the analysis of SN samples as well as that of single objects.Two main SN classes are discussed: radioactively-powered events and SNe interacting with their CSM.

Within the first group, we investigated the rare (~1% of core-collapse SNe) family of SN 1987A-like events. These SNe are found to be the explosion of compact, hydrogen-rich blue supergiant (BSG) stars, and to occur mainly in moderately low metallicity environs. We also studied a sample of 20 stripped-envelope (SE) SNe, which are also powered by the decay of radioactive 56Ni. These SNe are the result of the core-collapse of massive, hydrogen or even helium-poor stars stripped of their outer envelopes by line-driven winds and/or by the accretion onto companion stars.We investigated the differences among the early-time light curves of the subtypes forming the SE SN group (IIb, Ib, Ic, Ic-BL) and found that in all of them the 56Ni is strongly mixed out in the ejecta. This result suggests that the difference between helium-poor and helium-rich SNe is due to an actual lack of helium in SNe Ic and Ic-BL rather than to a different degree of 56Ni mixing.

Our work on CSM-interacting SNe include the study of a sample of SNe IIn, i.e. core-collapse SNe interacting with hydrogen-rich CSM, and the analysis of SN 2008J, a particularly rare event which we interpreted as the interaction of a thermonuclear SN Ia with a thick hydrogen-rich CSM. Spectral analysis of the SN IIn sample suggests that these SNe are likely to be the explosion of luminous blue variable stars (LBVs), although other channels are not excluded.

Place, publisher, year, edition, pages
Stockholm: Department of Astronomy, Stockholm University, 2014. 80 p.
Supernova, stellar evolution, metallicity, circumstellar interaction
National Category
Astronomy, Astrophysics and Cosmology
Research subject
urn:nbn:se:su:diva-108286 (URN)978-91-7649-030-3 (ISBN)
Public defence
2014-12-19, sal FB52, AlbaNova universitetscentrum, Roslagstullsbacken 21, Stockholm, 13:00 (English)

At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 5: Submitted.

Available from: 2014-11-27 Created: 2014-10-17 Last updated: 2014-11-20Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Taddia, FrancescoSollerman, Jesper
By organisation
Department of Astronomy
In the same journal
Astronomy and Astrophysics
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 30 hits
ReferencesLink to record
Permanent link

Direct link