Rapidly-Declining Hostless Type Ia Supernova KSP-OT-201509b from the KMTNet Supernova Program: Transitional Nature and Constraint on ${}^{56}$Ni Distribution and Progenitor Type

Abstract

We report the early discovery and multi-color ($BVI$) high-cadence light curve analyses of a rapidly-declining sub-Chandrasekhar Type Ia supernova KSP-OT-201509b (= AT2015cx) from the KMTNet Supernova Program. The Phillips parameter and color stretch parameter of KSP-OT-201509b (= AT2015cx) are $\Delta$$M_{B,15}$ $\simeq$ 1.62 mag and $s_{BV}$ $\simeq$ 0.54, respectively, at an inferred redshift of 0.072. These, together with other measured parameters (such as the strength of the secondary $I$-band peak, colors and luminosity), identify the source to be a rapidly-declining Type Ia of transitional nature that is closer to Branch Normal than 91bg-like. Its early light curve evolution and bolometric luminosity are consistent with those of homologously expanding ejecta powered by radioactive decay and a Type Ia SN explosion with 0.32 $\pm$ 0.01 $M_{\odot }$ of synthesized ${}^{56}$Ni mass, 0.84 $\pm$ 0.12 $M_{\odot }$ of ejecta mass and (0.61 $\pm$ 0.14) $\times$ 10${}^{51}$ erg of ejecta kinetic energy. While its $B-V$ and $V-I$ colors evolve largely synchronously with the changes in the $I$-band light curve as found in other supernovae, we also find the presence of an early redward evolution in $V-I$ prior to --10 days since peak. The bolometric light curve of the source is compatible with a stratified ${}^{56}$Ni distribution extended to shallow layers of the exploding progenitor. Comparisons between the observed light curves and those predicted from ejecta-companion interactions clearly disfavor Roche Lobe-filling companion stars at large separation distances, thus supporting a double-degenerate scenario for its origin. The lack of any apparent host galaxy in our deep stack images reaching a sensitivity limit of $\sim$ 28 $\mathrm{mag}\mathrm{arcse}{\mathrm{c}}^{-2}$ makes KSP-OT-201509b a hostless Type Ia supernova and offers new insights into supernova host galaxy environments.

arXiv comment39 pages, 20 figures, To appear in ApJ

References in corpus (96)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Astropy: A Community Python Package for Astronomy
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• A 2.4% Determination of the Local Value of the Hubble Constant
• Star Formation Histories, Abundances and Kinematics of Dwarf Galaxies in the Local Group
• SALT2: using distant supernovae to improve the use of Type Ia supernovae as distance indicators
• Nearby Supernova Rates from the Lick Observatory Supernova Search. II. The Observed Luminosity Functions and Fractions of Supernovae in a Complete Sample
• The Reddening-Free Decline Rate Versus Luminosity Relationship for Type Ia Supernovae
• A concise reference to (projected) Sersic R^{1/n} quantities, including Concentration, Profile Slopes, Petrosian indices, and Kron Magnitudes
• The Observed Offset Distribution of Gamma-Ray Bursts from Their Host Galaxies: A Robust Clue to the Nature of the Progenitors
• Rates and properties of type Ia supernovae as a function of mass and star-formation in their host galaxies
• Supernova 2011fe from an Exploding Carbon-Oxygen White Dwarf Star
• Seeing the Collision of a Supernova with its Companion Star
• A Common Explosion Mechanism for Type Ia Supernovae
• The Carnegie Supernova Project: First Photometry Data Release of Low-Redshift Type Ia Supernovae
• The size - virial radius relation of galaxies
• Constraints on the Progenitor System of the Type Ia Supernova SN 2011fe/PTF11kly
• Optical Photometry of the Type Ia SN 1999ee and the Type Ib/c SN 1999ex in IC 5179
• The Carnegie Supernova Project: Light Curve Fitting with SNooPy
• Double-detonation sub-Chandrasekhar supernovae: synthetic observables for minimum helium shell mass models
• Secondary Maximum in the Near-Infrared Lightcurves of Type Ia Supernovae
• Substructure and dynamics of the Fornax Cluster
• SiFTO: An Empirical Method for Fitting SNe Ia Light Curves
• The Broad-lined Type Ic SN 2003jd
• The Carnegie Supernova Project: Intrinsic Colors of Type Ia Supernovae
• Spectrophotometric time series of SN 2011fe from the Nearby Supernova Factory
• The Morphology of Type Ia Supernovae Light Curves
• The effects of seeing on Sersic profiles. II. The Moffat PSF
• A High Intrinsic Peculiarity Rate Among Type Ia Supernovae
• The Carnegie Supernova Project: Absolute Calibration and the Hubble Constant
• The Progenitors of Subluminous Type Ia Supernovae
• A Short GRB "No-Host'' Problem? Investigating Large Progenitor Offsets for Short GRBs with Optical Afterglows
• SN~2012cg: Evidence for Interaction Between a Normal Type Ia Supernova and a Non-Degenerate Binary Companion
• The underluminous Type Ia Supernova 2005bl and the class of objects similar to SN 1991bg
• Early Blue Excess from the Type Ia Supernova 2017cbv and Implications for Its Progenitor
• A New Method to Calibrate the Magnitudes of Type Ia Supernovae at Maximum Light
• Exploring the Potential Diversity of Early Type Ia Supernova Light Curves
• K2 Observations of SN 2018oh Reveal a Two-Component Rising Light Curve for a Type Ia Supernova
• Single or Double Degenerate Progenitors? Searching for Shock Emission in the SDSS-II Type Ia Supernovae
• Evidence for sub-Chandrasekhar-mass progenitors of Type Ia supernovae at the faint end of the width-luminosity relation
• Double Detonations with Thin, Modestly Enriched Helium Layers Can Make Normal Type Ia Supernovae
• Optical and Infrared Photometry of the Type Ia Supernovae 1999da, 1999dk, 1999gp, 2000bk, and 2000ce
• Constraints on Shallow 56Ni from the Early Lightcurves of Type Ia Supernovae
• Light and color curve properties of type Ia supernovae: Theory vs. Observations
• Strong near-infrared carbon in the Type Ia supernova iPTF13ebh
• Analysis of the Early-Time Optical Spectra of SN 2011fe in M101
• Seeing Double: ASASSN-18bt Exhibits a Two-Component Rise in the Early-Time K2 Light Curve
• The Type Ia Supernova 1999aw: a Probable 1999aa-like Event In a Low-Luminosity Host Galaxy
• Photometric and Spectroscopic Properties of Type Ia Supernova 2018oh with Early Excess Emission from the $Kepler$ 2 Observations
• Inside the whale: the structure and dynamics of the isolated Cetus dwarf spheroidal
• Two New Calcium-Rich Gap Transients in Group and Cluster Environments
• Constraining Type Ia Supernovae progenitors from three years of SNLS data
• The Young and Bright Type Ia Supernova ASASSN-14lp: Discovery, Early-Time Observations, First-Light Time, Distance to NGC 4666, and Progenitor Constraints
• Strong Evidence Against A Non-Degenerate Companion in SN 2012cg
• CANDELS Observations of the Environmental Dependence of the Color-Mass-Morphology Relation at z = 1.6
• Kinematics and Host-Galaxy Properties Suggest a Nuclear Origin for Calcium-Rich Supernova Progenitors
• Hypervelocity runaways from the Large Magellanic Cloud
• SN 2012fr: Ultraviolet, Optical, and Near-Infrared Light Curves of a Type Ia Supernova Observed Within a Day of Explosion
• Early Observations of the Type Ia Supernova iPTF 16abc: A Case of Interaction with Nearby, Unbound Material and/or Strong Ejecta Mixing
• Constraints on the origin of the first light from SN2014J
• A review of type Ia supernova spectra
• Red vs Blue: Early observations of thermonuclear supernovae reveal two distinct populations?
• PTF10ops - a subluminous, normal-width lightcurve Type Ia supernova in the middle of nowhere
• Tensile Strength of 67P/Churyumov-Gerasimenko Nucleus Material from Overhangs
• Determining the ${}^{56}$Ni distribution of type Ia supernovae from observations within days of explosion
• The red-sequence of 72 WINGS local galaxy clusters
• Early Time Light Curves of Type Ia Supernovae Observed with TESS
• Probing type Ia supernova properties using bolometric light curves from the Carnegie Supernova Project and the CfA Supernova Group
• Abundance stratification in Type Ia supernovae - V. SN 1986G bridging the gap between normal and subluminous SNe Ia
• Subluminous Type Ia Supernovae at High Redshift from the Supernova Legacy Survey
• The Spectacular Ultraviolet Flash From the Peculiar Type Ia Supernova 2019yvq
• Dwarf Galaxy Discoveries from the KMTNet Supernova Program I. The NGC 2784 Galaxy Group
• Imprints of the ejecta-companion interaction in Type Ia supernovae: main sequence, subgiant, and red giant companions
• An investigation of ${}^{56}$Ni shells as the source of early light curve bumps in type Ia supernovae
• Evidence for Sub-Chandrasekhar Mass Type Ia Supernovae from an Extensive Survey of Radiative Transfer Models
• On the type Ia supernovae 2007on and 2011iv: Evidence for Chandrasekhar-mass explosions at the faint end of the luminosity-width relationship
• Deep spectroscopic luminosity function of Abell 85: no evidence for a steep upturn of the faint-end slope
• Locations of Peculiar Supernovae as a Diagnostic of Their Origins
• Keck Observations of the Young Metal-Poor Host Galaxy of the Super-Chandrasekhar-Mass Type Ia Supernova SN 2007if
• Near-infrared light curves of Type Ia supernovae: Studying the properties of the second maximum
• Hubble Space Telescope observations of the host galaxies and environments of calcium-rich supernovae
• Two classes of fast-declining type Ia supernovae
• Early-phase photometry and spectroscopy of transitional Type Ia SN 2012ht: Direct constraint on the rise time
• Photometric redshifts for supernovae Ia in the Supernova Legacy Survey
• The first 48: Discovery and progenitor constraints on the Type Ia supernova 2013gy
• Confirmation of Hostless Type Ia Supernovae Using Hubble Space Telescope Imaging
• Type Ia supernovae have two physical width-luminosity relations and they favor sub-Chandrasekhar and direct collision models - II. Color evolution
• iPTF16abc and the population of Type Ia supernovae: Comparing the photospheric, transitional and nebular phases
• KSP-SN-2016kf: a long-rising H-rich Type II Supernova with unusually high ${}^{56}$Ni mass discovered in the KMTNet Supernova Program
• On the Rates of Type Ia Supernovae in Dwarf and Giant Hosts with ROTSE-IIIb
• Ultra-deep Large Binocular Camera U-band Imaging of the GOODS-North Field: Depth vs. Resolution
• SN 2015bp: adding to the growing population of transitional type Ia supernovae
• Dwarf Galaxy Discoveries from the KMTNet Supernova Program II. The NGC 3585 Group and Its Dynamical State
• Beacons In the Dark: Using Novae and Supernovae to Detect Dwarf Galaxies in the Local Universe

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