Environment-derived constraints on the progenitors of low-luminosity Type I supernovae (original) (raw)

The old environment of the faint calcium-rich supernova SN 2005cz

2010

The supernova SN 2005cz has recently attracted some attention, due to the fact that it was spectroscopically similar to type Ib supernovae (SNe), a class that is presumed to result from core-collapse of massive stars, yet it occurred in an elliptical galaxy, where one expects very few massive stars to exist. Two explanations for this remarkable event were put forward.

Rates and Properties of Type Ia Supernovae as a Function of Mass and Star Formation in Their Host Galaxies

The Astrophysical Journal, 2006

We show that Type Ia supernovae (SNe Ia) are formed within both very young and old stellar populations, with observed rates that depend on the stellar mass and mean star-formation rates (SFRs) of their host galaxies. Models where the SN Ia rate depends solely on host galaxy stellar mass are ruled out with >99% confidence. Our analysis is based on 100 spectroscopically-confirmed SNe Ia, plus 24 photometrically-classified events, all from the Supernova Legacy Survey (SNLS) and distributed over 0.2<z<0.75. Using multi-band photometry, we estimate stellar masses and SFRs for the SN Ia host galaxies by fitting their broad-band spectral energy distributions with the galaxy spectral synthesis code, PEGASE.2. We show that the SN Ia rate per unit mass is proportional to the specific SFR of the parent galaxies -more vigorously star-forming galaxies host more SNe Ia per unit stellar mass, broadly equivalent to the trend of increasing SN Ia rate in later-type galaxies seen in the local universe. Following earlier suggestions for a simple "two-component" model approximating the SN Ia rate, we find bivariate linear dependencies of the SN Ia rate on both the stellar masses and the mean SFRs of the host systems. We find that the SN Ia rate can be well represented as the sum of 5.3 ± 1.1 × 10 −14 SNe per year per unit stellar mass, and 3.9 ± 0.7 × 10 −4 SNe per year per M ⊙ yr −1 of star formation.

The rates of type Ia supernovae - II. Diversity of events at low and high redshifts

Monthly Notices of the Royal Astronomical Society, 2010

This paper investigates the possible systematic difference of type Ia supernovae (SNe Ia) properties related to the age and masses of the progenitors that could introduce a systematic bias between low-and high-redshift SNe Ia. The relation between the main features of the distribution of delay times and the masses of the progenitors is illustrated for the single (SD) and double degenerate (DD) models. Mixed models, which assume contributions from both the SD and DD channels, are also presented and tested versus the observed correlations between the SN Ia rates and the parent galaxy properties. It is shown that these correlations can be accounted for with both single-channel and mixed models, and that the rate in S0 and E galaxies may effectively provide clues on the contribution of SD progenitors to late epoch explosions. A wide range of masses for the CO white dwarf at the start of accretion is expected in almost all galaxy types; only in galaxies of the earliest types are the properties of the progenitors expected to be more uniform. For mixed models, late-type galaxies should host SD and DD explosions in comparable fractions, while in early-type galaxies DD explosions should largely prevail. Events hosted by star-forming galaxies span a wide range of delay times; prompt events could dominate only in the presence of a strong starburst. It is concluded that nearby SN Ia samples should well include the young, massive and hot progenitors that necessarily dominate at high redshift.

Rates, progenitors and cosmic mix of Type Ia supernovae

Monthly Notices of the Royal Astronomical Society, 2008

Following an episode of star formation, Type Ia supernova events occur over an extended period of time, following a distribution of delay times (DDT). We critically discuss some empirically based DDT functions that have been proposed in recent years, some favouring very early (prompt) events, other very late (tardy) ones, and therefore being mutually exclusive. We point out that in both the cases the derived DDT functions are affected by dubious assumptions, and therefore there is currently no ground for claiming either a DDT strongly peaked at early times, or at late ones. Theoretical DDT functions are known to accommodate both prompt as well as late SN Ia events, and can account for all available observational constraints. Recent observational evidence exist that both single and double degenerate precursors may be able of producing SN Ia events. We then explore on the basis of plausible theoretical models the possible variation with cosmic time of the mix between the events produced by the two different channels, which, in principle, could lead to systematic effects on the SN Ia properties with redshift.

Correlation of the rate of Type Ia supernovae with the parent galaxy properties: Light and shadows

Astronomy & Astrophysics, 2019

Context. The identification of the progenitors of Type Ia supernovae (SNIa) is extremely important in several astrophysical contexts, ranging from stellar evolution in close binary systems to evaluating cosmological parameters. Determining the distribution of the delay times (DTD) of SNIa progenitors can shed light on their nature. The DTD can be constrained by analysing the correlation between the SNIa rate and those properties of the parent galaxy which trace the average age of their stellar populations. Aims. We investigate the diagnostic capabilities of this correlation by examining its systematics with the various parameters at play: simple stellar population models, the adopted description for the star formation history (SFH) in galaxies, and the way in which the masses of the galaxies are evaluated. Methods. We computed models for the diagnostic correlations for a variety of input ingredients and for a few astrophysically motivated DTD laws appropriate for a wide range of pos...

The rate of type Ia Supernovae and the Star Formation History

AIP Conference Proceedings, 2009

The scaling of the rate of type Ia Supernovae (SNIa) with the parent galaxies' color provides information on the distribution of the delay times (DTD) of the SNIa progenitors. We show that this information appears to depend on the photometric bands used to trace the stellar age distribution and mass-to-light ratio in the parent galaxies. Using both U − V and B − K colors to constrain the star formation history, we model the SNIa rate as a function of morphological galaxy type for different DTDs. The comparison with the observed rate per unit B and K band luminosity yields consistent results, although the large error bars allow us to exclude only very flat and very narrow DTDs. The number of SNIa events per unit mass from one stellar generation results of ∼ 0.002-0.003 M −1 ⊙ .

Low luminosity Type II supernovae - II. Pointing towards moderate mass precursors

Monthly Notices of the Royal Astronomical Society, 2014

We present new data for five under-luminous type II-plateau supernovae (SNe IIP), namely SN 1999gn, SN 2002gd, SN 2003Z, SN 2004eg and SN 2006ov. This new sample of low-luminosity SNe IIP (LL SNe IIP) is analyzed together with similar objects studied in the past. All of them show a flat light curve plateau lasting about 100 days, an under luminous late-time exponential tail, intrinsic colours that are unusually red, and spectra showing prominent and narrow P-Cygni lines. A velocity of the ejected material below 10 3 km s −1 is inferred from measurements at the end of the plateau. The 56 Ni masses ejected in the explosion are very small ( 10 −2 M ⊙ ). We investigate the correlations among 56 Ni mass, expansion velocity of the ejecta and absolute magnitude in the middle of the plateau, confirming the main findings of Hamuy , according to which events showing brighter plateau and larger expansion velocities are expected to produce more 56 Ni. We propose that these faint objects represent the low luminosity tail of a continuous distribution in parameters space of SNe IIP. The physical properties of the progenitors at the explosion are estimated through the hydrodynamical modeling of the observables for two representative events of this class, namely SN 2005cs and SN 2008in. We find that the majority of LL SNe IIP, and quite possibly all, originate in the core-collapse of intermediate mass stars, in the mass range 10-15 M ⊙ .

Type-Ia Supernovae: New Clues to their Progenitors from the Delay Time Distribution

2010

Despite their prominent role in cosmography, little is yet known about the nature of type-Ia supernovae (SNe Ia), from the identity of their progenitor systems, through the evolution of those systems up to ignition and explosion, and to the causes of the environmental dependences of their observed properties. I briefly review some of those puzzles. I then focus on recent progress in reconstructing the SN Ia delay time distribution (DTD)-the SN rate versus time that would follow a hypothetical brief burst of star formation. A number of measurements of the DTD over the past two years, using different methods and based on SNe Ia in different environments and redshift ranges, are converging. At delays 1 < t < 10 Gyr, these measurements show a similar ∼ t −1 power-law shape, with similar normalizations. The DTD peaks at the shortest delays probed, but there is still some uncertainty regarding its precise shape in the range 0.1 < t < 1 Gyr. At face value, this result supports Ron Webbinks's (1984) idea of a double-degenerate progenitor origin for SNe Ia, but the numbers currently predicted by binary population synthesis models must be increased by factors of 3-10, at least. Single-degenerate progenitors may still play a role in producing short-delay SNe Ia, or perhaps all SNe Ia, if there are fundamental errors in the current modeling attempts.

Type Ia Supernovae: An Examination of Potential Progenitors and the Redshift Distribution

1997

We examine the possibility that supernovae type Ia (SN Ia) are produced by white dwarfs accreting from Roche-lobe filling evolved companions, under the assumption that a strong optically thick stellar wind from accretor is able to stabilize the mass transfer. We show that if a mass transfer phase on a thermal timescale precedes a nuclear burning driven phase, then such systems (of which the supersoft X-ray sources are a subgroup) can account for about 10 % of the inferred SN Ia rate. In addition, we examine the cosmic history of the supernova rate, and we show that the ratio of the rate of SN Ia to the rate of supernovae produced by massive stars (supernovae of types II, Ib, Ic) should increase from about z = 1 towards lower redshifts.

Nearby supernova host galaxies from the CALIFA Survey

Astronomy & Astrophysics, 2014

We use optical integral field spectroscopy (IFS) of nearby supernova (SN) host galaxies (0.005 < z < 0.03) provided by the Calar Alto Legacy Integral Field Area (CALIFA) Survey with the goal of finding correlations in the environmental parameters at the location of different SN types. In this first study of a series we focus on the properties related with star formation (SF). We recover the sequence in association of different SN types to the star-forming regions by using several indicators of the ongoing and recent SF related to both the ionized gas and the stellar populations. While the total ongoing SF is on average the same for the three SN types, SNe Ibc/IIb tend to occur closer to star-forming regions and in higher SF density locations than SNe II and SNe Ia; the latter shows the weakest correlation. SNe Ia host galaxies have masses that on average are ∼0.3-0.8 dex higher than those of the core collapse (CC) SNe hosts because the SNe Ia hosts contain a larger fraction of old stellar populations. Using the recent SN Ia delay-time distribution and the SFHs of the galaxies, we show that the SN Ia hosts in our sample are expected to produce twice as many SNe Ia as the CC SN hosts. Since both types occur in hosts with a similar SF rate and hence similar CC SN rate, this can explain the mass difference between the SN Ia and CC SN hosts, and reinforces the finding that at least part of the SNe Ia originate from very old progenitors. By comparing the mean SFH of the eight least massive galaxies with that of the massive SF SN Ia hosts, we find that the low-mass galaxies formed their stars during a longer time (0.65%, 24.46%, and 74.89% in the intervals 0-0.42 Gyr, 0.42-2.4 Gyr, and > 2.4 Gyr, respectively) than the massive SN Ia hosts (0.04%, 2.01%, and 97.95% in these intervals). We estimate that the low-mass galaxies produce ten times fewer SNe Ia and three times fewer CC SNe than the high-mass group. Therefore the ratio between the number of CC SNe and SNe Ia is expected to increase with decreasing galaxy mass. CC SNe tend to explode at positions with younger stellar populations than the galaxy average, but the galaxy properties at SNe Ia locations are one average the same as the global galaxy properties.