Article, 2024
1991T-like Supernovae* *This paper includes data gathered with the 6.5 m Magellan telescopes at Las Campanas Observatory, Chile.
The Astrophysical Journal Supplement Series,
ISSN
1538-4365,
0067-0049,
Volume 273,
1,
Page 16,
10.3847/1538-4365/ad4f7e
Contributors
Phillips, Mark M
0000-0003-2734-0796
[1]
Ashall, C R Angus C
0000-0002-5221-7557
[2]
Brown, Peter J
0000-0001-6272-5507
[3]
Galbany, L.
[4]
[5]
Tucker, M. A.
[6]
[7]
Burns, Christopher R
0000-0003-4625-6629
[8]
Contreras, Carlos
0000-0001-6293-9062
[1]
Hoeflich, Peter
0000-0002-4338-6586
[9]
Hsiao, Eric Y
0000-0003-1039-2928
[9]
Kumar, S.
[9]
[10]
Morrell, Nidia Irene
0000-0003-2535-3091
[1]
Uddin, Syed A
[3]
Baron, E.
[11]
[12]
[13]
Freedman, Wendy L
0000-0003-3431-9135
[14]
Krisciunas, Kevin L
0000-0002-6650-694X
[3]
Persson, Sven Eric
0000-0003-0554-7083
[8]
Piro, Anthony L
[8]
Shappee, B. J.
[15]
Stritzinger, Maximilian David
0000-0002-5571-1833
[16]
Suntzeff, Nicholas B
0000-0002-8102-181X
[3]
Chakraborty, Sudeshna
[9]
Kirshner, Robert P
0000-0002-1966-3942
[17]
[18]
Lu, J.
[9]
Marion, G. H.
[19]
Polin, Abigail E
0000-0002-1633-6495
[8]
[20]
Shahbandeh, M.
[9]
Affiliations
- [1]
Las Campanas Observatory
[NORA names:
Chile; America, South; OECD];
- [2]
Virginia Tech
[NORA names:
United States; America, North; OECD];
- [3]
Texas A&M University
[NORA names:
United States; America, North; OECD];
- [4]
Institut d'Estudis Espacials de Catalunya
[NORA names:
Spain; Europe, EU; OECD];
- [5]
Institute of Space Sciences
[NORA names:
Spain; Europe, EU; OECD];
(... more)
- [6]
CCAPP Fellow.
- [7]
The Ohio State University
[NORA names:
United States; America, North; OECD];
- [8]
Carnegie Observatories
[NORA names:
United States; America, North; OECD];
- [9]
Florida State University
[NORA names:
United States; America, North; OECD];
- [10]
University of Virginia
[NORA names:
United States; America, North; OECD];
- [11]
Planetary Science Institute
[NORA names:
United States; America, North; OECD];
- [12]
University of Oklahoma
[NORA names:
United States; America, North; OECD];
- [13]
Universität Hamburg
[NORA names:
Germany; Europe, EU; OECD];
- [14]
University of Chicago
[NORA names:
United States; America, North; OECD];
- [15]
University of Hawaiʻi at Mānoa
[NORA names:
United States; America, North; OECD];
- [16]
Aarhus University
[NORA names:
AU Aarhus University;
University; Denmark; Europe, EU; Nordic; OECD];
- [17]
Center for Astrophysics Harvard & Smithsonian
[NORA names:
United States; America, North; OECD];
- [18]
Gordon and Betty Moore Foundation
[NORA names:
United States; America, North; OECD];
- [19]
The University of Texas at Austin
[NORA names:
United States; America, North; OECD];
- [20]
California Institute of Technology
[NORA names:
United States; America, North; OECD]
(less)
Abstract
Understanding the nature of the luminous 1991T-like supernovae (SNe) is of great importance to SN cosmology as they are likely to have been more common in the early Universe. In this paper, we explore the observational properties of 1991T-like SNe to study their relationship to other luminous, slow-declining Type Ia supernovae (SNe Ia). From the spectroscopic and photometric criteria defined in Phillips et al., we identify 17 1991T-like SNe from the literature. Combining these objects with 10 1991T-like SNe from the Carnegie Supernova Project-II, the spectra, light curves, and colors of these events, along with their host galaxy properties, are examined in detail. We conclude that 1991T-like SNe are closely related in essentially all of their UV, optical, and near-infrared properties—as well as their host galaxy parameters—to the slow-declining subset of Branch core-normal SNe and to the intermediate 1999aa-like events, forming a continuum of luminous SNe Ia. The overriding difference between these three subgroups appears to be the extent to which 56Ni mixes into the ejecta, producing the premaximum spectra dominated by Fe iii absorption, the broader UV light curves, and the higher luminosities that characterize the 1991T-like events. Nevertheless, the association of 1991T-like SNe with the rare Type Ia circumstellar material SNe would seem to run counter to this hypothesis, in which case 1991T-like events may form a separate subclass of SNe Ia, possibly arising from single-degenerate progenitor systems.
Keywords
Carnegie,
Carnegie Supernova Project-II,
Chile,
Fe,
Ia supernovae,
Ia.,
Las,
Las Campanas Observatory,
Magellan Telescope,
Magellanic,
Observatory,
Project II,
SN cosmology,
SNe Ia,
SNe Ia.,
This paper,
Type Ia supernovae,
UV,
UV light curves,
University,
absorption,
association,
branches,
color,
continuum,
cosmology,
criteria,
curves,
data,
early universe,
ejecta,
events,
galaxy properties,
high luminosity,
host,
host galaxy properties,
hypothesis,
intermediate,
light curves,
literature,
luminosity,
mixing,
nature,
objective,
observed properties,
paper,
photometric criteria,
premaximum,
premaximum spectrum,
progenitor system,
properties,
properties—as,
relationship,
single-degenerate progenitor system,
spectra,
subclass,
subclass of SNe Ia,
subgroups,
subsets,
supernova,
system,
telescope,
type
Funders
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