J/ApJ/836/60 Bgri light curves of PTF11kmb and PTF12bho (Lunnan+, 2017)
Two new calcium-rich gap transients in group and cluster environments.
Lunnan R., Kasliwal M.M., Cao Y., Hangard L., Yaron O., Parrent J.T.,
McCully C., Gal-Yam A., Mulchaey J.S., Ben-Ami S., Filippenko A.V.,
Fremling C., Fruchter A.S., Howell D.A., Koda J., Kupfer T., Kulkarni S.R.,
Laher R., Masci F., Nugent P.E., Ofek E.O., Yagi M., Yan L.
<Astrophys. J., 836, 60-60 (2017)>
=2017ApJ...836...60L 2017ApJ...836...60L (SIMBAD/NED BibCode)
ADC_Keywords: Photometry, ugriz ; Supernovae
Keywords: supernovae: general;
supernovae: individual: (PTF11kmb, PTF12bho, PTF10hcw, SN 2005E)
Abstract:
We present the Palomar Transient Factory discoveries and the
photometric and spectroscopic observations of PTF11kmb and PTF12bho.
We show that both transients have properties consistent with the class
of calcium-rich gap transients, specifically lower peak luminosities
and rapid evolution compared to ordinary supernovae, and a nebular
spectrum dominated by [CaII] emission. A striking feature of both
transients is their host environments: PTF12bho is an intracluster
transient in the Coma Cluster, while PTF11kmb is located in a loose
galaxy group, at a physical offset ∼150kpc from the most likely host
galaxy. Deep Subaru imaging of PTF12bho rules out an underlying host
system to a limit of MR>-8.0mag, while Hubble Space Telescope
imaging of PTF11kmb reveals a marginal counterpart that, if real,
could be either a background galaxy or a globular cluster. We show
that the offset distribution of Ca-rich gap transients is
significantly more extreme than that seen for SNe Ia or even
short-hard gamma-ray bursts (sGRBs). Thus, if the offsets are caused
by a kick, they require higher kick velocities and/or longer merger
times than sGRBs. We also show that almost all Ca-rich transients
found to date are in group and cluster environments with elliptical
host galaxies, indicating a very old progenitor population; the remote
locations could partially be explained by these environments having
the largest fraction of stars in the intragroup/intracluster light
following galaxy-galaxy interactions.
Description:
The objects PTF11kmb and PTF12bho were found as part of the Palomar
Transient Factory (PTF).
PTF11kmb was discovered in data taken with the 48 inch Samuel Oschin
Telescope at Palomar Observatory (P48) on 2011 August 16.25 at a
magnitude r=19.8mag. A spectrum was taken with the Low Resolution
Imaging Spectrometer (LRIS) on the 10m Keck I telescope on 2011 August
28, showing SN features consistent with a SN Ib at a redshift z=0.017.
The source PTF12bho was discovered in P48 data on 2012 February 25.25
at a magnitude of r=20.52mag. A spectrum taken with LRIS on 2012 March
15 yields z=0.023 based on the SN features.
We obtained R- and g-band photometry of PTF11kmb and PTF12bho with the
P48 CFH12K camera. Additional follow-up photometry was conducted with
the automated 60-inch telescope at Palomar (P60) in the Bgri bands,
and with the Las Cumbres Observatory (LCO) Faulkes Telescope North in
gri.
PTF12bho was also observed with the Swift Ultra-Violet/Optical
Telescope (UVOT) and the Swift X-ray telescope (XRT) on 2012 March
17.8 for 3ks.
We obtained a sequence of spectra for both PTF11kmb and PTF12bho using
LRIS on Keck I, the DEep Imaging Multi-Object Spectrograph (DEIMOS) on
the 10m Keck II telescope, and the Double Spectrograph (DPSP) on the
200-inch Hale telescope at Palomar Observatory (P200) spanning 2011
Aug 28.5 to 2014 Jul 2.5.
We obtained deep imaging of the fields of PTF11kmb using WFC3/UVIS on
the Hubble Space Telescope (HST) through program GO-13864 (PI Kasliwal)
in 2015 Jul 12. This program also covered the field of SN 2005E (2014
Dec 10).
Objects:
--------------------------------------------------
RA (ICRS) DE Designation(s)
--------------------------------------------------
22 22 53.61 +36 17 36.5 PTF11kmb = PTF 11kmb
13 01 16.65 +28 01 18.5 PTF12bho = PTF 12bho
--------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 39 193 Photometry of PTF11kmb and PTF12bho
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See also:
J/ApJ/496/39 : Properties of poor groups of galaxies. I. (Zabludoff+ 1998)
J/ApJ/560/566 : K-band galaxy luminosity function from 2MASS (Kochanek+, 2001)
J/AJ/132/1729 : Hubble Ultra Deep Field BVI-dropout sources (Beckwith+, 2006)
J/ApJS/171/101 : GCs in the ACS Virgo cluster survey (Jordan+, 2007)
J/ApJ/696/870 : Catalina Real-time Transient Survey (CRTS) (Drake+, 2009)
J/ApJ/769/39 : SN Ibn PS1-12sk optical and NIR light curves (Sanders+, 2013)
J/A+A/593/A68 : PTF12os and iPTF13bvn spectra & light curves (Fremling+, 2016)
J/ApJ/827/90 : Spectroscopy of SNe Ib, IIb and Ic (Liu+, 2016)
J/ApJS/225/11 : Subaru-UDGs in the Coma cluster (Yagi+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- ID Object identifier
10- 16 F7.1 d MJD Modified Julian Date of observation
18- 22 F5.1 d Phase Rest-frame phase
24 A1 --- Filt Filter used in the observation (Bgri)
26- 30 F5.2 mag mag [18.7/22.1] Apparent AB magnitude in Filt (1)
32- 35 F4.2 mag e_mag [0.02/0.4] Uncertainty in mag
37- 39 A3 --- Tel Telescope code (2)
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Note (1): Corrected for foreground extinction according to
Schlafly & Finkbeiner (2011ApJ...737..103S 2011ApJ...737..103S).
Note (2): Telescope as follows:
P60 = Automated 60-inch telescope at Palomar;
P48 = The 48-inch Samuel Oschin Telescope at Palomar Observatory;
LCO = Las Cumbres Observatory Faulkes Telescope North.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 15-Sep-2017