- ID:
- ivo://CDS.VizieR/J/ApJ/872/135
- Title:
- Follow-up obs. of the type IIn SN KISS15s
- Short Name:
- J/ApJ/872/135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of an SN 1988Z-like type IIn supernova KISS15s found in a low-mass star-forming galaxy at redshift z=0.038 during the course of the Kiso Supernova Survey (KISS). KISS15s shows long-duration optical continuum and emission line light curves, indicating that KISS15s is powered by a continuous interaction between the expanding ejecta and dense circumstellar medium (CSM). The H{alpha} emission line profile can be decomposed into four Gaussians of narrow, intermediate, blueshifted intermediate, and broad velocity width components, with a full width at half maximum of <~100, ~2000, and ~14000km/s for the narrow, intermediate, and broad components, respectively. The presence of the blueshifted intermediate component, of which the line-of-sight velocity relative to the systemic velocity is about -5000km/s, suggests that the ejecta-CSM interaction region has an inhomogeneous morphology and anisotropic expansion velocity. We found that KISS15s shows increasing infrared continuum emission, which can be interpreted as hot dust thermal emission of T~1200K from newly formed dust in a cool, dense shell in the ejecta-CSM interaction region. The progenitor mass-loss rate, inferred from bolometric luminosity, is dM/dt~0.4M_{sun}_/yr ({nu}_w_/40km/s), where {nu}_w_ is the progenitor's stellar wind velocity. This implies that the progenitor of KISS15s was a red supergiant star or a luminous blue variable that had experienced a large mass loss in the centuries before the explosion.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/890/131
- Title:
- Follow-up of candidate counterparts of S190814bv
- Short Name:
- J/ApJ/890/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- On 2019 August 14, the Advanced LIGO and Virgo interferometers detected the high-significance gravitational wave (GW) signal S190814bv. The GW data indicated that the event resulted from a neutron star-black hole (NSBH) merger, or potentially a low-mass binary BH merger. Due to the low false-alarm rate and the precise localization (23deg^2^ at 90%), S190814bv presented the community with the best opportunity yet to directly observe an optical/near-infrared counterpart to an NSBH merger. To search for potential counterparts, the GROWTH Collaboration performed real-time image subtraction on six nights of public Dark Energy Camera images acquired in the 3 weeks following the merger, covering >98% of the localization probability. Using a worldwide network of follow-up facilities, we systematically undertook spectroscopy and imaging of optical counterpart candidates. Combining these data with a photometric redshift catalog, we ruled out each candidate as the counterpart to S190814bv and placed deep, uniform limits on the optical emission associated with S190814bv. For the nearest consistent GW distance, radiative transfer simulations of NSBH mergers constrain the ejecta mass of S190814bv to be M_ej_<0.04M_{sun}_ at polar viewing angles, or M_ej_<0.03M_{sun}_ if the opacity is {kappa}<2cm^2^g^-1^. Assuming a tidal deformability for the NS at the high end of the range compatible with GW170817 results, our limits would constrain the BH spin component aligned with the orbital momentum to be {chi}<0.7 for mass ratios Q<6, with weaker constraints for more compact NSs.
- ID:
- ivo://CDS.VizieR/J/ApJ/863/109
- Title:
- Follow-up optical observations of the SNIc SN2014L
- Short Name:
- J/ApJ/863/109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical spectroscopic and photometric observations of the nearby type Ic supernova (SN Ic) SN 2014L. This SN was discovered by the Tsinghua-NAOC Transient Survey (TNTS) in the nearby type-Sc spiral galaxy M99 (NGC 4254). Fitting to the early-time light curve indicates that SN 2014L was detected at only a few hours after the shock breakout, and it reached a peak brightness of M_V_=-17.73+/-0.28mag (L=[2.06+/-0.50]x10^42^erg/s) approximately 13 days later. SN 2014L shows a close resemblance to SN 2007gr in the photometric evolution, while it shows stronger absorption features of intermediate-mass elements (especially CaII) in the early-time spectra. Based on simple modeling of the observed light curves, we derived the mass of synthesized ^56^Ni as M_Ni_=0.075+/-0.025M_{sun}_, and the mass and total energy of the ejecta as M_ej_=1.00+/-0.20M_{sun}_ and E_ej_=1.45+/-0.25 foe, respectively. Given these typical explosion parameters, the early detection, and the extensive observations, we suggest that SN 2014L could be a template sample for the investigation of SNe Ic.
- ID:
- ivo://CDS.VizieR/J/ApJ/742/L18
- Title:
- Follow-up photometry of the SN IIb PTF 11eon
- Short Name:
- J/ApJ/742/L18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- On 2011 May 31 UT a supernova (SN) exploded in the nearby galaxy M51 (the Whirlpool Galaxy). We discovered this event using small telescopes equipped with CCD cameras and also detected it with the Palomar Transient Factory survey, rapidly confirming it to be a Type II SN. Here, we present multi-color ultraviolet through infrared photometry which is used to calculate the bolometric luminosity and a series of spectra. Our early-time observations indicate that SN 2011dh resulted from the explosion of a relatively compact progenitor star. Rapid shock-breakout cooling leads to relatively low temperatures in early-time spectra, compared to explosions of red supergiant stars, as well as a rapid early light curve decline. Optical spectra of SN 2011dh are dominated by H lines out to day 10 after explosion, after which HeI lines develop. This SN is likely a member of the cIIb (compact IIb) class, with progenitor radius larger than that of SN 2008ax and smaller than the eIIb (extended IIb) SN 1993J progenitor. Our data imply that the object identified in pre-explosion Hubble Space Telescope images at the SN location is possibly a companion to the progenitor or a blended source, and not the progenitor star itself, as its radius (~10^13^cm) would be highly inconsistent with constraints from our post-explosion spectra.
- ID:
- ivo://CDS.VizieR/J/MNRAS/475/193
- Title:
- Foundation Supernova Survey first data release
- Short Name:
- J/MNRAS/475/193
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Foundation Supernova Survey aims to provide a large, high-fidelity, homogeneous, and precisely calibrated low-redshift Type Ia supernova (SN Ia) sample for cosmology. The calibration of the current low-redshift SN sample is the largest component of systematic uncertainties for SN cosmology, and new data are necessary to make progress. We present the motivation, survey design, observation strategy, implementation, and first results for the Foundation Supernova Survey. We are using the Pan-STARRS telescope to obtain photometry for up to 800 SNe Ia at z<~0.1. This strategy has several unique advantages: (1) the Pan-STARRS system is a superbly calibrated telescopic system, (2) Pan-STARRS has observed 3/4 of the sky in grizyP1 making future template observations unnecessary, (3) we have a well-tested data-reduction pipeline, and (4) we have observed ~3000 high-redshift SNe Ia on this system. Here, we present our initial sample of 225 SN Ia grizP1 light curves, of which 180 pass all criteria for inclusion in a cosmological sample. The Foundation Supernova Survey already contains more cosmologically useful SNe Ia than all other published low-redshift SN Ia samples combined. We expect that the systematic uncertainties for the Foundation Supernova Sample will be two to three times smaller than other low-redshift samples. We find that our cosmologically useful sample has an intrinsic scatter of 0.111mag, smaller than other low-redshift samples. We perform detailed simulations showing that simply replacing the current low-redshift SN Ia sample with an equally sized Foundation sample will improve the precision on the dark energy equation-of-state parameter by 35 per cent, and the dark energy figure of merit by 72 per cent.
- ID:
- ivo://CDS.VizieR/J/MNRAS/452/4307
- Title:
- From optical to infrared photometry of SN 2013dy
- Short Name:
- J/MNRAS/452/4307
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- SN 2013dy is a Type Ia supernova (SN Ia) for which we have compiled an extraordinary data set spanning from 0.1 to ~500d after explosion. We present 10 epochs of ultraviolet (UV) through near-infrared (NIR) spectra with Hubble Space Telescope/Space Telescope Imaging Spectrograph, 47 epochs of optical spectra (15 of them having high resolution), and more than 500 photometric observations in the BVrRiIZYJH bands. SN 2013dy has a broad and slowly declining light curve ({Delta}m_15_(B)=0.92mag), shallow SiII {lambda}6355 absorption, and a low velocity gradient. We detect strong CII in our earliest spectra, probing unburned progenitor material in the outermost layers of the SN ejecta, but this feature fades within a few days. The UV continuum of SN 2013dy, which is strongly affected by the metal abundance of the progenitor star, suggests that SN 2013dy had a relatively high-metallicity progenitor. Examining one of the largest single set of high-resolution spectra for an SN Ia, we find no evidence of variable absorption from circumstellar material. Combining our UV spectra, NIR photometry, and high-cadence optical photometry, we construct a bolometric light curve, showing that SN 2013dy had a maximum luminosity of 10.0^+4.8^_-3.8_x10^42^erg/s. We compare the synthetic light curves and spectra of several models to SN 2013dy, finding that SN 2013dy is in good agreement with a solar-metallicity W7 model.
- ID:
- ivo://CDS.VizieR/J/other/Ap/52.40
- Title:
- FSS galaxies in southern hemisphere
- Short Name:
- J/other/Ap/52.40
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the properties of the 3838 galaxies that were monitored for SNe events, including newly determined morphologies and their DENIS and POSS-II/UKST I, 2MASS and DENIS J and K_s_ and 2MASS H magnitudes. We have compared 2MASS, DENIS and POSS-II/UKST IJK magnitudes in order to find possible systematic photometric shifts in the measurements. The DENIS and POSS-II/UKST I band magnitudes show large discrepancies (mean absolute difference of 0.4mag), mostly due to different spectral responses of the two instruments, with an important contribution (0.33mag rms) from the large uncertainties in the photometric calibration of the POSS-II and UKST photographic plates. In the other wavebands, the limiting near infrared magnitude, morphology, and inclination of the galaxies are the most influential factors which affect the determination of photometry of the galaxies. Nevertheless, no significant systematic differences have been found between of any pair of NIR magnitude measurements, except for a few percent of galaxies showing large discrepancies. This allows us to combine DENIS and 2MASS data for the J and K_s_ filters.
- ID:
- ivo://CDS.VizieR/J/ApJ/890/2
- Title:
- Full Spitzer IRAC obs. of SN1987A rise and fall
- Short Name:
- J/ApJ/890/2
- Date:
- 17 Jan 2022 00:19:48
- Publisher:
- CDS
- Description:
- Spitzer's final Infrared Array Camera observations of SN 1987A show the 3.6 and 4.5{mu}m emission from the equatorial ring (ER) continues a period of steady decline. Deconvolution of the images reveals that the emission is dominated by the ring, not the ejecta, and is brightest on the west side. Decomposition of the marginally resolved emission also confirms this, and shows that the west side of the ER has been brightening relative to the other portions of the ER. The infrared morphological changes resemble those seen in both the soft X-ray emission and the optical emission. The integrated ER light curves at 3.6 and 4.5{mu}m are more similar to the optical light curves than the soft X-ray light curve, though differences would be expected if dust is responsible for this emission and its destruction is rapid. Future observations with the James Webb Space Telescope will continue to monitor the ER evolution, and will reveal the true spectrum and nature of the material responsible for the broadband emission at 3.6 and 4.5{mu}m. The present observations also serendipitously reveal a nearby variable source, subsequently identified as a Be star, that has gone through a multiyear outburst during the course of these observations.
- ID:
- ivo://CDS.VizieR/J/other/ApSS/365.89
- Title:
- Gaia Alerts with LAMOST and SDSS
- Short Name:
- J/other/ApSS/365
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ESA-Gaia satellite is regularly producing Alerts on objects where photometric variability has been detected after several passages over the same region of the sky. The physical nature of these objects has often to be determined with the help of complementary observations from ground-based facilities. We have compared the list of Gaia Alerts (from the beginning in 2014 to Nov. 1st, 2018) with archival LAMOST and SDSS spectroscopic data. A search radius of 3" has been adopted. In using survey data, the date of the ground-based observation rarely corresponds to the date of the Alert, but this allows at least the identification of the source if it is persistent, or the host galaxy if the object was only transient like a supernova (SN). Some of the objects have several LAMOST observations, and we complemented this search by adding also SDSS DR15 data in order to look for long-term variability. A list of Gaia Nuclear Transients (GNT) from Kostrzewa-Rutkowska et al. (2018. 2018MNRAS.481..307K, Cat. J/MNRAS/481/307), has been included in this search also. We found 26 Gaia Alerts with spectra in LAMOST+SDSS labelled as stars, among which 12 have multi-epoch spectra. A majority of them are Cataclysmic Variables (CVs). Similarly, 206 Gaia Alerts have associated spectra labelled as galaxies, among which 49 have multi-epoch spectra. Those spectra were generally obtained on a date widely different from the Alert date, and are mostly emission-line galaxies with no particularity (except a few Seyferts), leading to the suspicion that most of the Alerts were due to a SN. As for the GNT list, we found 55 associated spectra labelled as galaxies, among them 13 with multi-epoch spectra. In these two galaxy samples, in only two cases, Gaia17aal and GNTJ170213+2543, was the date of the spectroscopic observation close enough to the Alert date: we find a trace of the SN itself in their LAMOST spectrum, both being now classified here as a type Ia SN. Compared to the galaxy sample from the Gaia alerts, the GNT sample has a higher proportion of AGNs, suggesting that some of the detected variations are also due to the AGN itself. Similarly for Quasars, we found only 30 Gaia Alerts but 68 GNT cases associated with single epoch quasar spectra in the databases. In addition to those, 12 plus 23 are quasars where multi-epoch spectra are available. For ten out of these 35, their multi-epoch spectra show appearance or disappearance of the broad Balmer lines and also variations in the continuum, qualifying them as "Changing Look Quasars" and therefore significantly increasing the available sample of such objects.
- ID:
- ivo://CDS.VizieR/J/MNRAS/481/307
- Title:
- Gaia Nuclear Transient (GNT) cand.
- Short Name:
- J/MNRAS/481/307
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The high spatial resolution and precise astrometry and photometry of the Gaia mission should make it particularly apt at discovering and resolving transients occurring in, or near, the centres of galaxies. Indeed, some nuclear transients are reported by the Gaia Science Alerts (GSA) team, but not a single confirmed tidal disruption event (TDE) has been published. In order to explore the sensitivity of GSA, we performed an independent and systematic search for nuclear transients using Gaia observations. Our transient search is driven from an input galaxy catalogue (derived from the Sloan Digital Sky Survey Release 12). We present a candidate detection metric that is independent from the existing GSA methodology, to see if Gaia Alerts are biased against the discovery of nuclear transients, and in particular which steps may have an impact. Our technique does require significant manual vetting of candidates, making implementation in the GSA system impractical for daily operations, although it could be run weekly, which for month-to-year long transients would make a scientifically valuable addition. Our search yielded 480 nuclear transients, 5 of which were alerted and published by GSA. The list of (in some cases ongoing) transients includes candidates for events related to enhanced accretion on to a super-massive black hole and TDEs. An implementation of the detection methodology and criteria used in this paper as an extension of GSA could open up the possibility for Gaia to fulfil the role as a main tool to find transient nuclear activity as predicted in the literature.
