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22581. Type IIn supernova photometry
ID:
ivo://CDS.VizieR/J/A+A/637/A73
Title:
Type IIn supernova photometry
Short Name:
J/A+A/637/A73
Date:
14 Jan 2022 08:08:51
Publisher:
CDS
Description:
The evolution of a Type IIn supernova (SN IIn) is governed by the interaction between the SN ejecta and a hydrogen-rich circumstellar medium (CSM). SNe IIn thus allow us to probe the late-time mass-loss history of their progenitor stars. We present optical photometry of a sample of 42 Type IIn supernovae, obtained by the Palomar Transient Factory (PTF) collaboration and its successor, the intermediate PTF (iPTF), from 2009 to 2017 using the 1.2m Samuel Oschin telescope and the 1.52m telescope at Palomar Observatory, California, USA.
22582. Type IIn Supernova SN 2010bt photometry
ID:
ivo://CDS.VizieR/J/ApJ/860/68
Title:
Type IIn Supernova SN 2010bt photometry
Short Name:
J/ApJ/860/68
Date:
21 Oct 2021
Publisher:
CDS
Description:
It is well known that massive stars (M>8M_{sun}_) evolve up to the collapse of the stellar core, resulting in most cases in a supernova (SN) explosion. Their heterogeneity is related mainly to different configurations of the progenitor star at the moment of the explosion and to their immediate environments. We present photometry and spectroscopy of SN 2010bt, which was classified as a Type IIn SN from a spectrum obtained soon after discovery and was observed extensively for about 2 months. After the seasonal interruption owing to its proximity to the Sun, the SN was below the detection threshold, indicative of a rapid luminosity decline. We can identify the likely progenitor with a very luminous star (log L/L_{sun}_~7) through comparison of Hubble Space Telescope images of the host galaxy prior to explosion with those of the SN obtained after maximum light. Such a luminosity is not expected for a quiescent star, but rather for a massive star in an active phase. This progenitor candidate was later confirmed via images taken in 2015 (~5yr post-discovery), in which no bright point source was detected at the SN position. Given these results and the SN behavior, we conclude that SN 2010bt was likely a Type IIn SN and that its progenitor was a massive star that experienced an outburst shortly before the final explosion, leading to a dense H-rich circumstellar environment around the SN progenitor.
22583. 26 type II-Plateau supernovae parameters
ID:
ivo://CDS.VizieR/J/ApJ/799/215
Title:
26 type II-Plateau supernovae parameters
Short Name:
J/ApJ/799/215
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a new self-consistent and versatile method that derives photospheric radius and temperature variations of Type II-Plateau supernovae based on their expansion velocities and photometric measurements. We apply the method to a sample of 26 well-observed, nearby supernovae with published light curves and velocities. We simultaneously fit ~230 velocity and ~6800mag measurements distributed over 21 photometric passbands spanning wavelengths from 0.19 to 2.2{mu}m. The light-curve differences among the Type II-Plateau supernovae are well modeled by assuming different rates of photospheric radius expansion, which we explain as different density profiles of the ejecta, and we argue that steeper density profiles result in flatter plateaus, if everything else remains unchanged. The steep luminosity decline of Type II-Linear supernovae is due to fast evolution of the photospheric temperature, which we verify with a successful fit of SN 1980K. Eliminating the need for theoretical supernova atmosphere models, we obtain self-consistent relative distances, reddenings, and nickel masses fully accounting for all internal model uncertainties and covariances. We use our global fit to estimate the time evolution of any missing band tailored specifically for each supernova, and we construct spectral energy distributions and bolometric light curves. We produce bolometric corrections for all filter combinations in our sample. We compare our model to the theoretical dilution factors and find good agreement for the B and V filters. Our results differ from the theory when the I, J, H, or K bands are included. We investigate the reddening law toward our supernovae and find reasonable agreement with standard R~3.1 reddening law in UBVRI bands. Results for other bands are inconclusive. We make our fitting code publicly available.
22584. Type IIP SN 2016bkv LCs and spectra
ID:
ivo://CDS.VizieR/J/ApJ/861/63
Title:
Type IIP SN 2016bkv LCs and spectra
Short Name:
J/ApJ/861/63
Date:
21 Oct 2021
Publisher:
CDS
Description:
While interaction with circumstellar material is known to play an important role in Type IIn supernovae (SNe), analyses of the more common SNe IIP and IIL have not traditionally included interaction as a significant power source. However, recent campaigns to observe SNe within days of explosion have revealed narrow emission lines of high-ionization species in the earliest spectra of luminous SNe II of all subclasses. These "flash ionization" features indicate the presence of a confined shell of material around the progenitor star. Here we present the first low-luminosity (LL) SN to show flash ionization features, SN 2016bkv. This SN peaked at MV = -16 mag and has H{alpha} expansion velocities under 1350 km s-1 around maximum light, placing it at the faint/slow end of the distribution of SNe IIP (similar to SN 2005cs). The light-curve shape of SN 2016bkv is also extreme among SNe IIP. A very strong initial peak could indicate additional luminosity from circumstellar interaction. A very small fall from the plateau to the nickel tail indicates unusually large production of radioactive nickel compared to other LL SNe IIP. A comparison between nebular spectra of SN 2016bkv and models raises the possibility that SN 2016bkv is an electron-capture supernova.
22585. Type II-P SN progenitor constraints
ID:
ivo://CDS.VizieR/J/MNRAS/395/1409
Title:
Type II-P SN progenitor constraints
Short Name:
J/MNRAS/395/1409
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a 10.5-yr, volume-limited (28-Mpc) search for supernova (SN) progenitor stars. In doing so we compile all SNe discovered within this volume (132, of which 27 per cent are Type Ia) and determine the relative rates of each subtype from literature studies. The core-collapse SNe break down into 59 per cent II-P and 29 per cent Ib/c, with the remainder being IIb (5 per cent), IIn (4 per cent) and II-L (3 per cent). There have been 20 II-P SNe with high-quality optical or near-infrared pre-explosion images that allow a meaningful search for the progenitor stars. In five cases they are clearly red supergiants, one case is unconstrained, two fall on compact coeval star clusters and the other twelve have no progenitor detected. We review and update all the available data for the host galaxies and SN environments (distance, metallicity and extinction) and determine masses and upper mass estimates for these 20 progenitor stars using the stars stellar evolutionary code and a single consistent homogeneous method. A maximum likelihood calculation suggests that the minimum stellar mass for a Type II-P to form is m_min_= 8.5^+1^_-1.5_M_{sun}_ and the maximum mass for II-P progenitors is m_max_= 16.5+/-1.5M_{sun}_, assuming a Salpeter initial mass function holds for the progenitor population (in the range {Gamma}=-1.35^+0.3^_-0.7_). The minimum mass is consistent with current estimates for the upper limit to white dwarf progenitor masses, but the maximum mass does not appear consistent with massive star populations in Local Group galaxies. Red supergiants in the Local Group have masses up to 25M_{sun}_ and the minimum mass to produce a Wolf-Rayet star in single star evolution (between solar and LMC metallicity) is similarly 25-30M_{sun}_. The reason we have not detected any high-mass red supergiant progenitors above 17M_{sun}_ is unclear, but we estimate that it is statistically significant at 2.4{sigma} confidence. Two simple reasons for this could be that we have systematically underestimated the progenitor masses due to dust extinction or that stars between 17-25M_{sun}_produce other kinds of SNe which are not II-P. We discuss these possibilities and find that neither provides a satisfactory solution. We term this discrepancy the 'red supergiant problem' and speculate that these stars could have core masses high enough to form black holes and SNe which are too faint to have been detected. We compare the ^56^Ni masses ejected in the SNe to the progenitor mass estimates and find that low-luminosity SNe with low ^56^Ni production are most likely to arise from explosions of low-mass progenitors near the mass threshold that can produce a core-collapse.
22586. Type IIP supernovae from Pan-STARRS1
ID:
ivo://CDS.VizieR/J/ApJ/799/208
Title:
Type IIP supernovae from Pan-STARRS1
Short Name:
J/ApJ/799/208
Date:
21 Oct 2021
Publisher:
CDS
Description:
In recent years, wide-field sky surveys providing deep multiband imaging have presented a new path for indirectly characterizing the progenitor populations of core-collapse supernovae (SNe): systematic light-curve studies. We assemble a set of 76 grizy-band Type IIP SN light curves from Pan-STARRS1, obtained over a constant survey program of 4yr and classified using both spectroscopy and machine-learning-based photometric techniques. We develop and apply a new Bayesian model for the full multiband evolution of each light curve in the sample. We find no evidence of a subpopulation of fast-declining explosions (historically referred to as "Type IIL" SNe). However, we identify a highly significant relation between the plateau phase decay rate and peak luminosity among our SNe IIP. These results argue in favor of a single parameter, likely determined by initial stellar mass, predominantly controlling the explosions of red supergiants. This relation could also be applied for SN cosmology, offering a standardizable candle good to an intrinsic scatter of <~0.2mag. We compare each light curve to physical models from hydrodynamic simulations to estimate progenitor initial masses and other properties of the Pan-STARRS1 Type IIP SN sample. We show that correction of systematic discrepancies between modeled and observed SN IIP light-curve properties and an expanded grid of progenitor properties are needed to enable robust progenitor inferences from multiband light-curve samples of this kind. This work will serve as a pathfinder for photometric studies of core-collapse SNe to be conducted through future wide-field transient searches.
22587. Type IIP supernova SN 2004dj radio observations
ID:
ivo://CDS.VizieR/J/ApJ/863/163
Title:
Type IIP supernova SN 2004dj radio observations
Short Name:
J/ApJ/863/163
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present radio observations and modeling of one of the nearest and brightest Type IIP supernova SN 2004dj exploded in the galaxy NGC2403 at a distance of ~3.5Mpc. Our observations span a wide frequency and temporal range of 0.24-43GHz and ~1d to 12yrs since the discovery. We model the radio light curves and spectra with the synchrotron emission. We estimate the mass-loss rate of the progenitor star to be dM/dt~1x10^-6^M_{sun}_/yr for a wind speed of 10km/s. We calculate the radio spectral indices using 1.06, 1.40, 5.00, and 8.46GHz flux density measurements at multiple epochs. We witness steepening in the spectral index values for an extended period predominantly at higher frequencies. We explain this as a signature of electron cooling happening at the supernova shock in the plateau phase of the supernova. We estimate the cooling timescales for inverse Compton cooling and synchrotron cooling and find that inverse Compton cooling is the dominant cooling process.
22588. Type II supernova light curves
ID:
ivo://CDS.VizieR/J/MNRAS/459/3939
Title:
Type II supernova light curves
Short Name:
J/MNRAS/459/3939
Date:
21 Oct 2021
Publisher:
CDS
Description:
High-quality collections of Type II supernova (SN) light curves are scarce because they evolve for hundreds of days, making follow-up observations time consuming and often extending over multiple observing seasons. In light of these difficulties, the diversity of SNe II is not fully understood. Here we present ultraviolet and optical photometry of 12 SNe II monitored by the Las Cumbres Observatory Global Telescope Network during 2013 to 2014, and compare them with previously studied SNe having well-sampled light curves. We explore SN II diversity by searching for correlations between the slope of the linear light-curve decay after maximum light (historically used to divide SNe II into IIL and IIP) and other measured physical properties. While SNe IIL are found to be on average more luminous than SNe IIP, SNe IIL do not appear to synthesize more ^56^Ni than SNe IIP. Finally, optical nebular spectra obtained for several SNe in our sample are found to be consistent with models of red supergiant progenitors in the 12-16M_{sun}_ range. Consequently, SNe IIL appear not to account for the deficit of massive red supergiants as SN II progenitors.
22589. Type-1 low-z AGN emission properties
ID:
ivo://CDS.VizieR/J/MNRAS/423/600
Title:
Type-1 low-z AGN emission properties
Short Name:
J/MNRAS/423/600
Date:
21 Oct 2021
Publisher:
CDS
Description:
We analyze the emission properties of a new sample of 3,579 type 1 AGN, selected from the SDSS DR7 based on the detection of broad H-{alpha} emission. The sample extends over a broad H-{alpha} luminosity L_bHa_ of 10^40^-10^44^erg/s and a broad H-{alpha} FWHM of 1,000-25,000km/s, which covers the range of black hole mass 10^6^<M_BH_/M{sun}<10^9.5^ and luminosity in Eddington units 10^-3^<L/L_Edd_<1. We combine ROSAT, GALEX and 2MASS observations to form the SED from 2.2um to 2keV. We find the following: 1. The distribution of the H-{alpha} FWHM values is independent of luminosity. 2. The observed mean optical-UV SED is well matched by a fixed shape SED of luminous quasars, which scales linearly with L_bHa_, and a host galaxy contribution. 3. The host galaxy r-band (fibre) luminosity function follows well the luminosity function of inactive non-emission line galaxies (NEG), consistent with a fixed fraction of ~3% of NEG hosting an AGN, regardless of the host luminosity. 4. The hosts of lower luminosity AGN have a mean z band luminosity and u-z colour which are identical to NEG with the same redshift distribution. With increasing L_bHa_ the AGN hosts become bluer and less luminous than NEG. The implied increasing star formation rate with L_bHa_ is consistent with the relation for SDSS type 2 AGN of similar bolometric luminosity. 5. The optical-UV SED of the more luminous AGN shows a small dispersion, consistent with dust reddening of a blue SED, as expected for thermal thin accretion disc emission. 6. There is a rather tight relation of {nu}L_{nu}_(2keV) and L_bHa_, which provides a useful probe for unobscured (true) type 2 AGN. 7. The primary parameter which drives the X-ray to UV emission ratio is the luminosity, rather than M_BH_ or L/L_Edd_.
22590. Type-2 QSOs in XMM-COSMOS
ID:
ivo://CDS.VizieR/J/A+A/535/A80
Title:
Type-2 QSOs in XMM-COSMOS
Short Name:
J/A+A/535/A80
Date:
21 Oct 2021
Publisher:
CDS
Description:
We explore the connection between black hole growth at the center of obscured quasars selected from the XMM-COSMOS survey and the physical properties of their host galaxies. We study a bolometric regime (<Lbol>=8x10^45^erg/s) where several theoretical models invoke major galaxy mergers as the main fueling channel for black hole accretion. To derive robust estimates of the host galaxy properties, we use an SED fitting technique to distinguish the AGN and host galaxy emission. We evaluate the effect on galaxy properties estimates of being unable to remove the nuclear emission from the SED. The superb multi-wavelength coverage of the COSMOS field allows us to obtain reliable estimates of the total stellar masses and star formation rates (SFRs) of the hosts. We supplement this information with a morphological analysis of the ACS/HST images, optical spectroscopy, and an X-ray spectral analysis.

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