- ID:
- ivo://CDS.VizieR/J/A+A/526/A28
- Title:
- SDSS-II supernovae NTT and NOT spectroscopy
- Short Name:
- J/A+A/526/A28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Sloan Digital Sky Survey II (SDSS-II) Supernova Survey, conducted between 2005 and 2007, was designed to detect a large number of type Ia supernovae around z~0.2, the redshift "gap" between low-z and high-z supernova searches. The survey has provided multi-band (ugriz) photometric lightcurves for variable targets, and supernova candidates were scheduled for spectroscopic observations, primarily to provide supernova classification and accurate redshifts. We present supernova spectra obtained in 2006 and 2007 using the New Technology Telescope (NTT) and the Nordic Optical Telescope (NOT). We provide an atlas of supernova spectra in the range z=0.03-0.32 that complements the well-sampled lightcurves from SDSS-II in the forthcoming three-year SDSS supernova cosmology analysis. The sample can, for example, be used for spectral studies of type Ia supernovae, which are critical for understanding potential systematic effects when supernovae are used to determine cosmological distances. The spectra were reduced in a uniform manner, and special care was taken in estimating the uncertainties for the different processing steps. Host-galaxy light was subtracted when possible and the supernova type fitted using the SuperNova IDentification code (SNID). We also present comparisons between spectral and photometric dating using SALT lightcurve fits to the photometry from SDSS-II, as well as the global distribution of our sample in terms of the lightcurve parameters: stretch and colour.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/136/2306
- Title:
- SDSS-II Supernova survey, 2005
- Short Name:
- J/AJ/136/2306
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ugriz light curves for 146 spectroscopically-confirmed or spectroscopically-probable Type Ia supernovae (SNe) from the 2005 season of the Sloan Digital Sky Survey-II Supernova (SN) survey. The light curves have been constructed using a photometric technique that we call scene modeling, which is described in detail here; the major feature is that SN brightnesses are extracted from a stack of images without spatial resampling or convolution of the image data. This procedure produces accurate photometry along with accurate estimates of the statistical uncertainty, and can be used to derive photometry taken with multiple telescopes. We discuss various tests of this technique that demonstrate its capabilities. We also describe the methodology used for the calibration of the photometry, and present calibrated magnitudes and fluxes for all of the spectroscopic SNe Ia from the 2005 season.
- ID:
- ivo://CDS.VizieR/J/other/Sci/348.413
- Title:
- Sgr A East SNR multiwavelength images
- Short Name:
- J/other/Sci/348.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Dust formation in supernova ejecta is currently the leading candidate to explain the large quantities of dust observed in the distant, early universe. However, it is unclear whether the ejecta-formed dust can survive the hot interior of the supernova remnant (SNR). We present infrared observations of ~0.02 solar masses of warm (~100 kelvin) dust seen near the center of the ~10,000-year-old Sagittarius A East SNR at the Galactic center. Our findings indicate the detection of dust within an older SNR that is expanding into a relatively dense surrounding medium (electron density ~10^3^ centimeters^-3^) and has survived the passage of the reverse shock. The results suggest that supernovae may be the dominant dust-production mechanism in the dense environment of galaxies of the early universe.
- ID:
- ivo://CDS.VizieR/J/ApJS/220/20
- Title:
- Si and Ca high-velocity features in SNe Ia
- Short Name:
- J/ApJS/220/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The high-velocity features (HVFs) in optical spectra of type Ia supernovae (SNe Ia) are examined with a large sample including very early-time spectra (e.g., t<-7days). Multiple Gaussian fits are applied to examine the HVFs and their evolutions, using constraints on expansion velocities for the same species (i.e., SiII5972 and SiII6355). We find that strong HVFs tend to appear in SNe Ia with smaller decline rates (e.g., {Delta}m_15_(B)<~1.4mag), clarifying that the finding by Childress et al. (2014MNRAS.437..338C) for the Ca-HVFs in near-maximum-light spectra applies both to the Si-HVFs and Ca-HVFs in the earlier phase. The Si-HVFs seem to be more common in rapidly expanding SNe Ia, which is different from the earlier result that Ca-HVFs are associated with SNe Ia that have slower SiII6355 velocities at maximum light (i.e., V^Si^_max_). Moreover, SNe Ia with both stronger HVFs at early phases and larger V^Si^_max_ are found to have noticeably redder B-V colors and to occur preferentially in the inner regions of their host galaxies, while those with stronger HVFs but smaller V^Si^_max_ show opposite tendencies, suggesting that these two subclasses have different explosion environments and their HVFs may have different origins. We further examine the relationships between the absorption features of SiII6355 and CaII IR lines, and find that their photospheric components are well correlated in velocity and strength but that the corresponding HVFs show larger scatter. These results cannot be explained with ionization and/or thermal processes alone, and different mechanisms are required for the creation of HVF-forming regions in SNe Ia.
- ID:
- ivo://CDS.VizieR/J/MNRAS/408/827
- Title:
- Simulations of supernova explosions
- Short Name:
- J/MNRAS/408/827
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present radiation-hydrodynamic simulations of core-collapse supernova (SN) explosions, artificially generated by driving a piston at the base of the envelope of a rotating or non-rotating red-supergiant progenitor star. We search for trends in ejecta kinematics in the resulting Type II-Plateau (II-P) SN, exploring dependencies with explosion energy and pre-SN stellar-evolution model.
- ID:
- ivo://CDS.VizieR/II/333
- Title:
- Sloan Digital Sky Survey-II Supernova Survey
- Short Name:
- II/333
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper describes the data release of the Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey conducted between 2005 and 2007. Light curves, spectra, classifications, and ancillary data are presented for 10,258 variable and transient sources discovered through repeat ugriz imaging of SDSS Stripe 82, a 300deg^2^ area along the celestial equator. This data release is comprised of all transient sources brighter than r~=22.5mag with no history of variability prior to 2004. Dedicated spectroscopic observations were performed on a subset of 889 transients, as well as spectra for thousands of transient host galaxies using the SDSS-III BOSS spectrographs. Photometric classifications are provided for the candidates with good multi-color light curves that were not observed spectroscopically. From these observations, 4607 transients are either spectroscopically confirmed, or likely to be, supernovae, making this the largest sample of supernova candidates ever compiled. We present a new method for SN host-galaxy identification and derive host-galaxy properties including stellar masses, star-formation rates, and the average stellar population ages from our SDSS multi-band photometry. We derive SALT2 distance moduli for a total of 1443 SN Ia with spectroscopic redshifts as well as photometric redshifts for a further 677 purely-photometric SN Ia candidates. Using the spectroscopically confirmed subset of the three-year SDSS-II SN Ia sample and assuming a flat {LAMBDA}CDM cosmology, we determine {OMETA}_M_=0.315+/-0.093 (statistical error only) and detect a non-zero cosmological constant at 5.7{sigma}.
- ID:
- ivo://CDS.VizieR/J/AJ/135/1766
- Title:
- Sloan Digital Sky Survey-II supernova survey
- Short Name:
- J/AJ/135/1766
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents spectroscopy of supernovae (SNe) discovered in the first season of the Sloan Digital Sky Survey-II SN Survey. This program searches for and measures multi-band light curves of SNe in the redshift range z=0.05-0.4, complementing existing surveys at lower and higher redshifts. Our goal is to better characterize the SN population, with a particular focus on SNe Ia, improving their utility as cosmological distance indicators and as probes of dark energy. Our SN spectroscopy program features rapid-response observations using telescopes of a range of apertures, and provides confirmation of the SN and host-galaxy types as well as precise redshifts. We describe here the target identification and prioritization, data reduction, redshift measurement, and classification of 129 SNe Ia, 16 spectroscopically probable SNe Ia, 7 SNe Ib/c, and 11 SNe II from the first season. We also describe our efforts to measure and remove the substantial host-galaxy contamination existing in the majority of our SN spectra.
- ID:
- ivo://CDS.VizieR/J/A+A/561/A146
- Title:
- SN 2010ae optical spectra
- Short Name:
- J/A+A/561/A146
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A comprehensive set of optical and near-infrared (NIR) photometry and spectroscopy is presented for the faint and fast 2008ha-like supernova (SN) 2010ae.
- ID:
- ivo://CDS.VizieR/J/A+A/541/L1
- Title:
- SN 1987A images at 350 and 870um
- Short Name:
- J/A+A/541/L1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Supernova 1987A (SN 1987A) in the neighbouring Large Magellanic Cloud offers a superb opportunity to follow the evolution of a supernova and its remnant in unprecedented detail. Recently, far-infrared (far-IR) and sub-mm emission was detected from the direction of SN 1987A, which was interpreted as due to the emission from dust, possibly freshly synthesized in the SN ejecta. To better constrain the location and hence origin of the far-IR and sub-mm emission in SN 1987A, we have attempted to resolve the object in that part of the electro-magnetic spectrum.
280. SN 1987A 3mm image
- ID:
- ivo://CDS.VizieR/J/A+A/541/L2
- Title:
- SN 1987A 3mm image
- Short Name:
- J/A+A/541/L2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The proximity of core-collapse supernova 1987A (SN 1987A) in the Large Magellanic Cloud (LMC) and its rapid evolution make it a unique case study of the development of a young supernova remnant. We aim at resolving the remnant of SN 1987A for the first time in the 3-mm band (at 94GHz).
