- ID:
- ivo://CDS.VizieR/J/A+A/611/A58
- Title:
- SN 2007on and SN 2011iv light curves
- Short Name:
- J/A+A/611/A58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of ultraviolet (UV) to near-infrared observations of the fast-declining Type Ia supernovae (SNe Ia) 2007on and 2011iv, hosted by the Fornax cluster member NGC 1404. The B-band light curves of SN 2007on and SN 2011iv are characterised by {Delta}m15(B) decline-rate values of 1.96mag and 1.77mag, respectively. Although they have similar decline rates, their peak B- and H-band magnitudes differ by ~0.60mag and ~0.35mag, respectively. After correcting for the luminosity vs. decline rate and the luminosity vs. colour relations, the peak B-band and H-band light curves provide distances that differ by ~14% and ~9%, respectively. These findings serve as a cautionary tale for the use of transitional SNe Ia located in early-type hosts in the quest to measure cosmological parameters. Interestingly, even though SN 2011iv is brighter and bluer at early times, by three weeks past maximum and extending over several months, its B-V colour is 0.12mag redder than that of SN 2007on. To reconcile this unusual behaviour, we turn to guidance from a suite of spherical one-dimensional Chandrasekhar-mass delayed-detonation explosion models. In this context, ^56^Ni production depends on both the so-called transition density and the central density of the progenitor white dwarf. To first order, the transition density drives the luminosity-width relation, while the central density is an important second-order parameter. Within this context, the differences in the B-V colour evolution along the Lira regime suggest that the progenitor of SN 2011iv had a higher central density than SN 2007on.
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Search Results
6042. SN PS1-11ap light curves
- ID:
- ivo://CDS.VizieR/J/MNRAS/437/656
- Title:
- SN PS1-11ap light curves
- Short Name:
- J/MNRAS/437/656
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical photometric and spectroscopic coverage of the superluminous supernova (SLSN) PS1-11ap, discovered with the Pan-STARRS1 Medium Deep Survey at z=0.524. This intrinsically blue transient rose slowly to reach a peak magnitude of M_u_=-21.4mag and bolometric luminosity of 8x10^43^erg/s before settling on to a relatively shallow gradient of decline. The observed decline is significantly slower than those of the SLSNe-Ic which have been the focus of much recent attention. Spectroscopic similarities with the lower redshift SN2007bi and a decline rate similar to 56Co decay time-scale initially indicated that this transient could be a candidate for a pair instability supernova (PISN) explosion. Overall the transient appears quite similar to SN2007bi and the lower redshift object PTF12dam. The extensive data set, from 30d before peak to 230d after, allows a detailed and quantitative comparison with published models of PISN explosions. We find that the PS1-11ap data do not match these model explosion parameters well, supporting the recent claim that these SNe are not pair instability explosions. We show that PS1-11ap has many features in common with the faster declining SLSNe-Ic, and the light-curve evolution can also be quantitatively explained by the magnetar spin-down model. At a redshift of z=0.524, the observer-frame optical coverage provides comprehensive rest-frame UV data and allows us to compare it with the SLSNe recently found at high redshifts between z=2 and 4. While these high-z explosions are still plausible PISN candidates, they match the photometric evolution of PS1-11ap and hence could be counterparts to this lower redshift transient.
6043. SN type Ia luminosities
- ID:
- ivo://CDS.VizieR/J/ApJ/645/488
- Title:
- SN type Ia luminosities
- Short Name:
- J/ApJ/645/488
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A sample of 109 Type Ia supernovae (SNe Ia) with recession velocity <~30000km/s is compiled from published SN Ia light curves to explore the expansion rate of the local universe. Based on the color parameter {Delta}C_12_ and the decline rate {delta}m15, we found that the average absorption-to-reddening ratios for SN Ia host galaxies are R_UBVI_=4.37+/-0.25, 3.33+/-0.11, 2.30+/-0.11, and 1.18+/-0.11, which are systematically lower than the standard values in the Galaxy. We investigated the correlations of the intrinsic luminosity with light-curve decline rate, color index, and SN environmental parameters.
- ID:
- ivo://CDS.VizieR/J/A+A/602/A93
- Title:
- SN Type Ibn OGLE-2014-SN-131 lightcurves
- Short Name:
- J/A+A/602/A93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Type Ibn supernovae (SNe Ibn) are thought to be the core-collapse explosions of massive stars whose ejecta interact with He-rich circumstellar material (CSM). We report the discovery of a SN Ibn, with the longest rise-time ever observed, OGLE-2014-SN-131. We discuss the potential powering mechanisms and the progenitor nature of this peculiar stripped-envelope (SE), circumstellar-interacting SN. Optical photometry and spectroscopy were obtained with multiple telescopes including VLT, NTT, and GROND. We compare light curves and spectra with those of other known SNe Ibn and Ibc. CSM velocities are derived from the spectral analysis. The SN light curve is modeled under different assumptions about its powering mechanism (56Ni decay, CSM-interaction, magnetar) in order to estimate the SN progenitor parameters. OGLE-2014-SN-131 spectroscopically resembles SNe Ibn such as SN 2010al. Its peak luminosity and post-peak colors are also similar to those of other SNe Ibn. However, it shows an unprecedentedly long rise-time and a much broader light curve compared to other SNe Ibn. Its bolometric light curve can be reproduced by magnetar and CSM-interaction models, but not by a 56Ni-decay powering model. To explain the unusually long rise-time, the broad light curve, the light curve decline, and the spectra characterized by narrow emission lines, we favor a powering mechanism where the SN ejecta are interacting with a dense CSM. The progenitor of OGLE-2014-SN-131 was likely a Wolf-Rayet star with a mass greater than that of a typical SN Ibn progenitor, which expelled the CSM that the SN is interacting with.
- ID:
- ivo://CDS.VizieR/J/ApJS/208/7
- Title:
- Sodium excess objects. I. SDSS-DR7
- Short Name:
- J/ApJS/208/7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Several studies have reported the presence of sodium excess objects having neutral atomic absorption lines at 5895{AA} (Na.D) and 8190{AA} that are deeper than expected based on stellar population models that match the stellar continuum. The origin of these lines is therefore hotly debated. van Dokkum & Conroy (2010Natur.468..940V) proposed that low-mass stars (<~0.3M_{sun}_) are more prevalent in massive early-type galaxies, which may lead to a strong Na I 8190 line strength. It is necessary to test this prediction, however, against other prominent optical line indices such as Na.D, Mg b, and Fe 5270, which can be measured with a significantly higher signal-to-noise ratio than Na I 8190. We identified a new sample of roughly 1000 Na.D excess objects (NEOs; ~8% of galaxies in the sample) based on Na.D line strength in the redshift range 0.00<=z<=0.08 from the Sloan Digital Sky Survey (SDSS) DR7 through detailed analysis of galaxy spectra. We explore the properties of these new objects here. The novelty of this work is that the galaxies were carefully identified through direct visual inspection of SDSS images, and we systematically compared the properties of NEOs and those of a control sample of galaxies with normal Na.D line strengths. We note that the majority of galaxies with high velocity dispersions ({sigma}_e_>250km/s) show Na.D excesses.
- ID:
- ivo://CDS.VizieR/J/ApJ/874/16
- Title:
- SOFIA Massive Star Formation Survey. II. 7 protostars
- Short Name:
- J/ApJ/874/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multiwavelength images observed with SOFIA-FORCAST from ~10 to 40{mu}m of seven high luminosity massive protostars, as part of the SOFIA Massive Star Formation Survey. Source morphologies at these wavelengths appear to be influenced by outflow cavities and extinction from dense gas surrounding the protostars. Using these images, we build spectral energy distributions (SEDs) of the protostars, also including archival data from Spitzer, Herschel, and other facilities. Radiative transfer (RT) models of Zhang & Tan (2018ApJ...853...18Z), based on Turbulent Core Accretion theory, are then fit to the SEDs to estimate key properties of the protostars. Considering the best five models fit to each source, the protostars have masses m*~12-64M_{sun}_ accreting at rates of dm/dt_*_~10^-4^-10^-3^M_{sun}_/yr inside cores of initial masses M_c_~100-500M_{sun}_ embedded in clumps with mass surface densities {Sigma}_cl_~0.1-3g/cm^2^ and span a luminosity range of 10^4^-10^6^L_{sun}_. Compared with the first eight protostars in Paper I (De Buizer+ 2017ApJ...843...33D), the sources analyzed here are more luminous and, thus, likely to be more massive protostars. They are often in a clustered environment or have a companion protostar relatively nearby. From the range of parameter space of the models, we do not see any evidence that {Sigma}cl needs to be high to form these massive stars. For most sources, the RT models provide reasonable fits to the SEDs, though the cold clump material often influences the long wavelength fitting. However, for sources in very clustered environments, the model SEDs may not be such a good description of the data, indicating potential limitations of the models for these regions.
- ID:
- ivo://CDS.VizieR/J/A+A/399/995
- Title:
- SOFI and ISOCAM observations of Cha II
- Short Name:
- J/A+A/399/995
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An infrared study including ISOCAM images at 6.75 and 14.3{mu}m of a large portion (28'x26') of the Chamaeleon II dark cloud and sub-arcsec resolution JHKs images of the central (4.9'x4.9') area is presented. Combining the ISOCAM observations with J and Ks photometry obtained with DENIS, we have found 12 young stars, of which 8 are previously identified sources.
- ID:
- ivo://CDS.VizieR/J/A+A/631/A150
- Title:
- Softly X-raying the gamma-ray sky I.
- Short Name:
- J/A+A/631/A150
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- BL Lac objects are an extreme type of active galactic nuclei (AGNs) that belong to the largest population of gamma-ray sources: blazars. This class of AGNs shows a double-bumped spectral energy distribution that is commonly described in terms of a synchrotron self-Compton (SSC) emission process, whereas the low-energy component that dominates their emission between the infrared and the X-ray band is tightly connected to the high-energy component that peaks in the gamma-rays. Two strong connections that link radio and mid-infrared emission of blazars to the emission in the gamma-ray band are well established. They constitute the basis for associating gamma-ray sources with their low-energy counterparts. We searched for a possible link between X-ray and gamma-ray emissions for the subclass of BL Lacs using all archival Swift/XRT observations combined with Fermi data for a selected sample of 351 sources. Analyzing ~2400ks of Swift/XRT observations that were carried out until December 2018, we discovered that above the gamma-ray flux threshold Fgamma~=3x10^-12^erg/cm^2^/s, 96% of all Fermi BL Lacs have an X-ray counterpart that is detected with signal-to-noise ratio >3. We did not find any correlation or clear trend between X-ray and gamma-ray fluxes and/or spectral shapes, but we discovered a correlation between the X-ray flux and the mid-infrared color. Finally, we discuss on a possible interpretation of our results in the SSC framework.
- ID:
- ivo://CDS.VizieR/J/A+A/422/337
- Title:
- Solar EUV Post-Eruptive Arcades
- Short Name:
- J/A+A/422/337
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Extreme ultraviolet Imaging Telescope (EIT) on board the Solar and Heliospheric Observatory (SOHO) spacecraft provides unique observations of dynamic processes in the low corona. The EIT 195{AA} data taken from 1997 to the end of 2002 were investigated to study the basic physical properties of post-eruptive arcades (PEAs) and their relationship with coronal mass ejections (CMEs) as detected by SOHO/LASCO (Large Angle Spectrometric Coronagraph). Over the investigated time period, 236 PEA events have been identified in total. For each PEA, its EUV lifetime as derived from the emission time at 195{AA}, its heliographic position and length, and its corresponding photospheric source region inferred from SOHO/MDI (Michelson Doppler Imager) data has been studied, as well as the variation of these parameters over the investigated phase of solar cycle 23.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A31
- Title:
- Solar-like oscillations in Kepler DR25 SC data
- Short Name:
- J/A+A/657/A31
- Date:
- 21 Mar 2022 09:22:47
- Publisher:
- CDS
- Description:
- During the survey phase of the Kepler mission, several thousand stars were observed in short cadence, allowing for the detection of solar-like oscillations in more than 500 main-sequence and subgiant stars. These detections showed the power of asteroseismology in determining fundamental stellar parameters. However, the Kepler Science Office discovered an issue in the calibration that affected half of the store of short-cadence data, leading to a new data release (DR25) with corrections on the light curves. In this work, we re-analyzed the one-month time series of the Kepler survey phase to search for solar-like oscillations that might have been missed when using the previous data release. We studied the seismic parameters of 99 stars, among which there are 46 targets with new reported solar-like oscillations, increasing, by around 8%, the known sample of solar-like stars with an asteroseismic analysis of the short-cadence data from this mission. The majority of these stars have mid- to high-resolution spectroscopy publicly available with the LAMOST and APOGEE surveys, respectively, as well as precise Gaia parallaxes. We computed the masses and radii using seismic scaling relations and we find that this new sample features massive stars (above 1.2M_{sun}_ and up to 2M_{sun}_) and subgiants. We determined the granulation parameters and amplitude of the modes, which agree with the scaling relations derived for dwarfs and subgiants. The stars studied here are slightly fainter than the previously known sample of main-sequence and subgiants with asteroseismic detections. We also studied the surface rotation and magnetic activity levels of those stars. Our sample of 99 stars has similar levels of activity compared to the previously known sample and is in the same range as the Sun between the minimum and maximum of its activity cycle. We find that for seven stars, a possible blend could be the reason for the non-detection with the early data release. Finally, we compared the radii obtained from the scaling relations with the Gaia ones and we find that the Gaia radii are overestimated by 4.4%, on average, compared to the seismic radii, with a scatter of 12.3% and a decreasing trend according to the evolutionary stage. In addition, for homogeneity purposes, we re-analyzed the DR25 of the main-sequence and subgiant stars with solar-like oscillations that were previously detected and, as a result, we provide the global seismic parameters for a total of 525 stars.
