J/ApJ/793/38 Palomar Transient Factory photometric observations (Arcavi+, 2014)
A continuum of H- to He-rich tidal disruption candidates with a preference
for E+A galaxies.
Arcavi I., Gal-Yam A., Sullivan M., Pan Y.-C., Cenko S.B., Horesh A.,
Ofek E.O., De Cia A., Yan L., Yang C.-W., Howell D.A., Tal D.,
Kulkarni S.R., Tendulkar S.P., Tang S., Xu D., Sternberg A., Cohen J.G.,
Bloom J.S., Nugent P.E., Kasliwal M.M., Perley D.A., Quimby R.M.,
Miller A.A., Theissen C.A., Laher R.R.
<Astrophys. J., 793, 38 (2014)>
=2014ApJ...793...38A 2014ApJ...793...38A (SIMBAD/NED BibCode)
ADC_Keywords: Supernovae ; Galaxies, optical ; Photometry
Keywords: accretion, accretion disks - galaxies: nuclei -
quasars: supermassive black holes
Abstract:
We present the results of a Palomar Transient Factory (PTF) archival
search for blue transients that lie in the magnitude range between
"normal" core-collapse and superluminous supernovae (i.e., with
-21≤MR(peak)≤-19). Of the six events found after excluding all
interacting Type IIn and Ia-CSM supernovae, three (PTF09ge, 09axc, and
09djl) are coincident with the centers of their hosts, one (10iam) is
offset from the center, and a precise offset cannot be determined for
two (10nuj and 11glr). All the central events have similar rise times
to the He-rich tidal disruption candidate PS1-10jh, and the event with
the best-sampled light curve also has similar colors and power-law
decay. Spectroscopically, PTF09ge is He-rich, while PTF09axc and 09djl
display broad hydrogen features around peak magnitude. All three
central events are in low star formation hosts, two of which are E+A
galaxies. Our spectrum of the host of PS1-10jh displays similar
properties. PTF10iam, the one offset event, is different
photometrically and spectroscopically from the central events, and its
host displays a higher star formation rate. Finding no obvious
evidence for ongoing galactic nuclei activity or recent star
formation, we conclude that the three central transients likely arise
from the tidal disruption of a star by a supermassive black hole. We
compare the spectra of these events to tidal disruption candidates
from the literature and find that all of these objects can be unified
on a continuous scale of spectral properties. The accumulated evidence
of this expanded sample strongly supports a tidal disruption origin
for this class of nuclear transients.
Description:
All the events from our archival search were discovered by the Palomar
48 inch Oschin Schmidt Telescope (P48) as part of the PTF survey using
the Mould R-band filter. We obtained photometric observations in the R
and g bands using P48, and in g, r, and i bands with the Palomar 60
inch telescope (P60; Cenko et al. 2006PASP..118.1396C 2006PASP..118.1396C). Initial
processing of the P48 images was conducted by the Infrared Processing
and Analysis Center (IPAC; Laher et al. 2014PASP..126..674L 2014PASP..126..674L).
Photometry was extracted using a custom PSF fitting routine (e.g.,
Sullivan et al. 2006AJ....131..960S 2006AJ....131..960S), which measures the transient
flux after image subtraction (using template images taken before the
outburst or long after it faded).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sources.dat 32 6 List of studied sources
table2.dat 46 543 Photometric observations
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See also:
II/313 : Palomar Transient Factory (PTF) photometric catalog 1.0 (Ofek+, 2012)
Byte-by-byte Description of file: sources.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Simbad rigth ascension (J2000)
4- 5 I2 min RAm Simbad rigth ascension (J2000)
7- 11 F5.2 s RAs Simbad rigth ascension (J2000)
13 A1 --- DE- Simbad declination sign (J2000)
14- 15 I2 deg DEd Simbad declination (J2000)
17- 18 I2 arcmin DEm Simbad declination (J2000)
20- 23 F4.1 arcsec DEs Simbad declination (J2000)
25- 27 A3 --- --- [PTF]
28- 32 A5 --- PTF Object identifier (PTF YYaaa in Simbad)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [PTF]
4- 8 A5 --- PTF Object identifier (PTF YYaaa in Simbad)
11- 13 A3 --- Tel Telescope identifier (1)
15 A1 --- Filter [gri] Filter used in the observation
17- 27 F11.3 d JD Julian Date of the observation
29 A1 --- l_mag Upper 3σ non-detection limit flag on mag
30- 36 F7.4 mag mag Observed magnitude in Filter
38- 46 F9.7 mag e_mag ? Error in mag
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Note (1): Identifier as follows:
P48 = Palomar 48-inch Oschin Schmidt Telescope;
P60 = Palomar 60-inch telescope.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 18-Apr-2017