J/ApJ/924/121 Transients in the centers of PS & QBS galaxies (Arcavi+, 2022)
Types of transients in the centers of post-starburst and quiescent Balmer-strong
galaxies.
Arcavi I., Nyiha I., French K.D.
<Astrophys. J., 924, 121 (2022)>
=2022ApJ...924..121A 2022ApJ...924..121A
ADC_Keywords: Galaxies, photometry; Transient; Supernovae; Redshifts
Keywords: E+A galaxies ; Supernovae ; Tidal disruption
Abstract:
Tidal disruption events (TDEs) have been found to show a preference
for post-starburst (PS) and quiescent Balmer-strong (QBS) galaxies.
This preference can be used to help find TDEs in transient surveys.
But what other transients might "contaminate" such a search, and by
how much? We examine all reported transients coincident with the
centers of galaxies in the French & Zabludoff (2018, J/ApJ/868/99)
catalog of spectroscopically confirmed PS and QBS galaxies and
photometrically identified PS and QBS galaxy candidates. We find that
TDEs and Type Ia supernovae (SNe) are the only types of transients
classified in the centers of these galaxies (aside from one active
galactic nucleus flare), with Type Ia SNe being 8.3±0.2 times more
prevalent than TDEs (1σ confidence bounds). This factor is
∼2.7 times lower than in a control sample of quiescent galaxies.
Narrowing the sample to spectroscopically confirmed QBS galaxies does
not change these statistics much. In spectroscopically confirmed PS
galaxies, however, TDEs are the ones that outnumber Type Ia SNe
2±0.6 to 1. Unfortunately, there are few such galaxies in the
catalog. By classifying transients from the entire catalog, three
times more TDEs are expected to be found, but with a ∼16 times larger
Type Ia SN contamination. We use the public ZTF photometric archive to
search for possibly missed TDEs in the French & Zabludoff (2018)
galaxies. We find three unclassified clear transients-none of which
are likely missed TDEs based on their light-curve colors.
Description:
For ZTF20abxphdt, we obtained a spectrum with the Floyds spectrograph
mounted on the Las Cumbres Observatory 2m telescope in Haleakala,
Hawaii.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 107 101 Events in the TNS that are coincident to within 1"
with the center of a galaxy in the
French & Zabludoff 2018, J/ApJ/868/99 (FZ18) catalog
(see Section 4.1)
table4.dat 82 395 Events in the ZTF public alert stream which are
coincident to within 1" with the center of a
galaxy in the FZ18 catalog (see Section 4.2)
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See also:
II/357 : The Dark Energy Survey (DES): Data Release 1 (Abbott+, 2018)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/ApJ/793/38 : Palomar Transient Factory photometric obs. (Arcavi+, 2014)
J/ApJ/844/46 : Phot. of the transient event iPTF16fnl (Blagorodnova+, 2017)
J/ApJ/868/99 : Identifying post-starburst galaxies from surveys (French+, 2018)
http://www.wis-tns.org/ : Transient Name Server (TNS) home page
http://lasair.roe.ac.uk/watchlist/321/ : Latest ZTF Transient Alerts Map
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- TName IAU name from the TNS
13- 21 F9.5 deg RAdeg [1.4/346.6] Right Ascension (J2000)
23- 31 F9.5 deg DEdeg [-38.3/77.7] Declination (J2000)
33- 46 A14 --- TClass TNS classification (1)
48- 97 A50 --- OName Other name(s)
99-102 A4 --- FZ18 Tables numbers from FZ18
104-107 F4.2 arcsec Sep [0.04/0.99] Separation from host
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Note (1): Class as follows:
SN Ia = 25 occurrences
TDE = 3 occurrences
AGN = 1 occurrence
Galaxy = 1 occurrence
Not Classified = 71 occurrences
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [ZTF]
4- 12 A9 --- ZTF ZTF name (YYaaaaaaa)
14- 22 F9.5 deg RAdeg Right Ascension (J2000)
24- 32 F9.5 deg DEdeg [-26.5/80.3] Declination (J2000)
34- 36 I3 --- Ndet [2/573] Number of detections
38- 44 A7 --- Class Sherlock class (1)
46- 56 A11 --- TName TNS name
58- 63 A6 --- TClass TNS class
65- 69 A5 --- FZ18 Tables numbers from FZ18
71- 76 A6 --- Rank Light-curve rank
78- 82 F5.3 --- z [0.026/0.4]? Redshift from the host galaxy
spectrum, if available, or from other sources (2)
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Note (1): Sherlock (http://lasair.roe.ac.uk/sherlock) is a contextual
classifier which provides an initial classification of every non-moving
object by performing a spatial cross-match against a large number of
catalogs such as nearby galaxies, variable stars and active galactic
nuceli (see Section 4.2 of Smith+ (2020PASP..132h5002S 2020PASP..132h5002S) for more
details). Class as follows:
AGN = Active Galactic Nucleus (26 occurrences)
NT = Nuclear Transient; i.e. a transient consistent with the
nucleus of a galaxy (307 occurrences)
SN = Supernova (23 occurrences)
VS = Variable Star (38 occurrences)
UNCLEAR = 1 occurrence
Note (2): We search SDSS DR16 and the 2dF Galaxy Redshift Survey (2dFGRS;
Colless+ 2003, see VII/250) for host galaxy redshifts of the ZTF
photometrically selected events coincident with the center of a galaxy
in the FZ18 catalog.
For ZTF20abxphdt, a "Gold" event, we obtained our own FLOYDS spectrum
of the host galaxy and measured the redshift to be 0.0675 from narrow
CaII H+K and NaI D absorption features (Figure 7).
See Section 5.2.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 24-Aug-2023