J/MNRAS/448/1206 Superluminous supernovae in faint galaxies (McCrum+, 2015)
Selecting superluminous supernovae in faint galaxies from the first year of
the Pan-STARRS1 Medium Deep Survey.
McCrum M., Smartt S.J., Rest A., Smith K., Kotak R., Rodney S.A.,
Young D.R., Chornock R., Berger E., Foley R.J., Fraser M., Wright D.,
Scolnic D., Tonry J.L., Urata Y., Huang K., Pastorello A., Botticella M.T.,
Valenti S., Mattila S., Kankare E., Farrow D.J., Huber M.E., Stubbs C.W.,
Kirshner R.P., Bresolin F., Burgett W.S., Chambers K.C., Draper P.W.,
Flewelling H., Jedicke R., Kaiser N., Magnier E.A., Metcalfe N.,
Morgan J.S., Price P.A., Sweeney W., Wainscoat R.J., Waters C.
<Mon. Not. R. Astron. Soc., 448, 1206-1231 (2015)>
=2015MNRAS.448.1206M 2015MNRAS.448.1206M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Supernovae ; Photometry
Keywords: supernovae: general - supernovae: individual: PS1-10pm -
supernovae: individual: PS1-10ahf
Abstract:
The Pan-STARRS1 (PS1) survey has obtained imaging in five bands
(griz yP1) over 10 Medium Deep Survey (MDS) fields covering a total
of 70 square degrees. This paper describes the search for apparently
hostless supernovae (SNe) within the first year of PS1 MDS data with
an aim of discovering superluminous supernovae (SLSNe). A total of 249
hostless transients were discovered down to a limiting magnitude of
MAB∼23.5, of which 76 were classified as Type Ia supernovae
(SNe Ia). There were 57 SNe with complete light curves that are likely
core-collapse SNe (CCSNe) or type Ic SLSNe and 12 of these have had
spectra taken. Of these 12 hostless, non-Type Ia SNe, 7 were SLSNe of
type Ic at redshifts between 0.5 and 1.4. This illustrates that the
discovery rate of type Ic SLSNe can be maximized by concentrating on
hostless transients and removing normal SNe Ia. We present data for
two possible SLSNe; PS1-10pm (z=1.206) and PS1-10ahf (z=1.1), and
estimate the rate of type Ic SLSNe to be between
3+3-2x10-5 and 8+2-1x10-5 that of the CCSN rate within
0.3≤z≤1.4 by applying a Monte Carlo technique. The rate of slowly
evolving, type Ic SLSNe (such as SN2007bi) is estimated as a factor of
10 lower than this range.
Description:
From the period starting February 25th 2010 and ending July 9th 2011,
249 hostless transients or "orphans" were discovered in the PS1 Medium
Deep fields. AN orphan is defined as an object that is >3.4" away from
the centre of a catalogued galaxy or point source brighter than
approximately 23.5m (in any of the gP1 rP1 iP1 filters that the
transient was detected in).
The PS1 observations are obtained through a set of five broadband
filters, which we have designated as gP1, rP1, iP1, zP1, and
yP1. Although the filter system for PS1 has much in common with that
used in previous surveys, such as SDSS (Abazajian et al.,
2009ApJS..182..543A 2009ApJS..182..543A), there are important differences. The gP1 filter
extends 20nm redward of gSDSS, paying the price of 5577Å emission
for greater sensitivity and lower systematics for photometric
redshifts, and the zP1 filter is cut off at 930nm, giving it a
different response than the detector response which defined zSDSS.
SDSS has no corresponding yP1 filter. Further information on the
passband shapes is described in Stubbs et al. (2010ApJS..191..376S 2010ApJS..191..376S).
The PS1 photometric system and its response is covered in detailed in
Tonry et al. (2012ApJ...750...99T 2012ApJ...750...99T, Cat. J/ApJ/750/99). Photometry is
in the "natural" PS1 system, m=-2.5log(flux)+m', with a single
zeropoint adjustment m' made in each band to conform to the AB
magnitude scale.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 112 28 The 28 spectroscopically confirmed PS1 SN Ia
table4.dat 71 48 The 48 plausible PS1 SN Ia, classified using the
soft and psnid photometric classification codes
table5.dat 109 12 *The 12 confirmed PS1 CCSNe
table6.dat 63 17 *The 17 plausible PS1 CCSNe
table7.dat 136 75 Observed photometry for PS1-10pm
table10.dat 105 64 Observed photometry for PS1-10ahf
tablea2.dat 67 28 The 28 SN-like orphans
tablea3.dat 53 116 The 116 unknown orphans
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Note on table5.dat: Of note is the high percentage of SLSNe Ic confirmed.
Note on table6.dat: The values in the soft and psnid columns represent the
probability that the object is classified as the type II subclass listed.
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See also:
J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Field Field
6- 16 A11 --- Name Supernova PS1 designation
(PS1-NNAAA or PS1-NNNNNNN)
17 A1 --- n_Name [*] Note on Name (1)
19- 26 F8.4 deg RAdeg Right ascension (J2000)
28- 34 F7.4 deg DEdeg Declination (J2000)
36- 40 F5.3 --- zsp Spectroscopic redshift
42- 47 F6.3 mag rP1mag Peak rP1 magnitude
49- 53 F5.3 mag e_rP1mag rms uncertainty on peak rP1 magnitude
55- 62 A8 --- Tel Telescope
64- 73 A10 "date" Date Observation date
75 A1 --- Note [*] Note for spectral classification (2)
77-112 A36 --- Ref References
--------------------------------------------------------------------------------
Note (1): The MD06 object PS1-11acn is designated as PTF11dws in the cited
source of classification.
Note (2): * = spectral classifications for these objects as SNe Ia can be found
in Rest et al. (2014ApJ...795...44R 2014ApJ...795...44R)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Field Field
6- 16 A11 --- Name Supernova PS1 designation (PS1-NNAAA)
18- 25 F8.4 deg RAdeg Right ascension (J2000)
27- 34 F8.4 deg DEdeg Declination (J2000)
36- 40 F5.3 --- soft ?=- Probability that the object is classified
as an SN Ia with soft photometric
classification code (G1)
42- 46 F5.3 --- psnid ?=- Probability that the object is classified
as an SN Ia with psnid photometric
classification code (G1)
48- 52 F5.3 --- zph ?=- Photometric redshift
54- 58 F5.3 --- e_zph ?=- rms uncertainty on zph
60- 65 F6.3 mag rP1mag ?=- Peak rP1 magnitude
67- 71 F5.3 mag e_rP1mag ? rms uncertainty on peak rP1 magnitude
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Field Field
6- 16 A11 --- Name Supernova PS1 designation (PS1-NNAAA)
17 A1 --- n_Name [a*] Note on Name (1)
19- 26 F8.4 deg RAdeg Right ascension (J2000)
28- 35 F8.4 deg DEdeg Declination (J2000)
37- 48 A12 --- Type Type
50- 54 F5.3 --- zsp Spectroscopic redshift
57- 61 F5.3 --- soft ?=- Probability that the object is classified
as the SNe type given in Typesoft column
(soft photometric classification code) (G1)
63- 65 A3 --- Typesoft Type from soft
67- 71 F5.3 --- psnid ?=- Probability that the object is classified
as the SNe type given in Typepsnid column
(psnid photometric classification code) (G1)
73- 75 A3 --- Typepsnid Type from psnid
77- 82 F6.3 mag rP1mag ?=- Peak rP1 magnitude
84- 88 F5.3 mag e_rP1mag ? rms uncertainty on peak rP1 magnitude
90- 92 A3 --- Inst Instrument
94-103 A10 "date" Date Observation date
105-109 A5 --- Ref Reference(s) (2)
--------------------------------------------------------------------------------
Note (1): Notes as follows:
* = the two objects are explored further in this paper.
a = PS1-10afx has been shown to be a lensed SN Ia, and is included here for
completeness of objects, although we do not use it in any of our rate
estimates
Note (2): References as follows:
1 = McCrum et al. (2014MNRAS.437..656M 2014MNRAS.437..656M)
2 = this paper
3 = Lunnan et al. (2014ApJ...787..138L 2014ApJ...787..138L)
4 = Chomiuk et al. (2011ApJ...743..114C 2011ApJ...743..114C)
5 = Chornock et al. (2013ApJ...767..162C 2013ApJ...767..162C)
6 = Quimby et al. (2013MNRAS.431..912Q 2013MNRAS.431..912Q, 2013ApJ...768L..20Q 2013ApJ...768L..20Q)
7 = Quimby et al. (2014Sci...344..396Q 2014Sci...344..396Q)
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Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Field Field
6- 16 A11 --- Name Supernova PS1 designation (PS1-NNAAA)
18- 25 F8.4 deg RAdeg Right ascension (J2000)
27- 34 F8.4 deg DEdeg Declination (J2000)
36- 38 A3 --- Type Type
40- 44 F5.3 --- soft ?=- Probability that the object is classified
as the type II subclass listed with soft
photometric classification code (G1)
46- 50 F5.3 --- psnid ?=- Probability that the object is classified
as the type II subclass listed with psnid
photometric classification code (G1)
52- 57 F6.3 mag rP1mag ?=- Peak rP1 magnitude
59- 63 F5.3 mag e_rP1mag ? rms uncertainty on peak rP1 magnitude
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "date" Date Observation date
12- 19 F8.2 d MJD Modified Julian date
21- 27 F7.2 d Phase Phase, in observer frame, not rest frame
29 A1 --- l_gP1mag Limit flag on gP1mag
30- 34 F5.2 mag gP1mag ?=- gP1 (481nm) magnitude (1)
36- 39 F4.2 mag e_gP1mag ? rms uncertainty on gP1mag
42 A1 --- l_rP1mag Limit flag on rP1mag
43- 47 F5.2 mag rP1mag ?=- rP1 (617nm) magnitude (1)
49- 52 F4.2 mag e_rP1mag ? rms uncertainty on rP1mag
55 A1 --- l_iP1mag Limit flag on iP1mag
56- 60 F5.2 mag iP1mag ?=- iP1 (752nm) magnitude (1)
62- 65 F4.2 mag e_iP1mag ? rms uncertainty on iP1mag
68 A1 --- l_zP1mag Limit flag on zP1mag
69- 73 F5.2 mag zP1mag ?=- zP1 (866nm) magnitude (1)
75- 78 F4.2 mag e_zP1mag ? rms uncertainty on zP1mag
82- 86 F5.2 mag gmag ?=- g magnitude (1)
88- 91 F4.2 mag e_gmag ? rms uncertainty on gmag
95- 99 F5.2 mag rmag ?=- r magnitude (1)
101-104 F4.2 mag e_rmag ? rms uncertainty on rmag
108-112 F5.2 mag imag ?=- i magnitude (1)
114-117 F4.2 mag e_imag ? rms uncertainty on imag
121-125 F5.2 mag zmag ?=- z magnitude (1)
127-130 F4.2 mag e_zmag ? rms uncertainty on zmag
134-136 A3 --- Tel Telescope
--------------------------------------------------------------------------------
Note (1): No K-corrections have been applied.
Note that the PS1 observations have had any flux from a previous reference
image removed through image subtraction (although note that no host object
can be seen at the location of PS1-10pm) whereas the late time WHT and GN
observations have not.
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Byte-by-byte Description of file: table10.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "date" Date Observation date
12- 19 F8.2 d MJD Modified Julian date
21- 27 F7.2 d Phase Phase, in observer frame, not rest frame, as
more than one possible redshift value is
presented in the text
29 A1 --- l_rP1mag Limit flag on rP1mag
30- 34 F5.2 mag rP1mag ?=- rP1 (617nm) magnitude (1)
36- 39 F4.2 mag e_rP1mag ? rms uncertainty on rP1mag
41 A1 --- l_iP1mag Limit flag on iP1mag
42- 46 F5.2 mag iP1mag ?=- iP1 (752nm) magnitude (1)
48- 51 F4.2 mag e_iP1mag ? rms uncertainty on iP1mag
53 A1 --- l_zP1mag Limit flag on zP1mag
54- 58 F5.2 mag zP1mag ?=- zP1 (866nm) magnitude (1)
60- 63 F4.2 mag e_zP1mag ? rms uncertainty on zP1mag
66- 70 F5.2 mag rmag ?=- r magnitude (1)
72- 75 F4.2 mag e_rmag ? rms uncertainty on rmag
78- 82 F5.2 mag imag ?=- i magnitude (1)
84- 87 F4.2 mag e_imag ? rms uncertainty on imag
91- 95 F5.2 mag zmag ? z magnitude (1)
97-100 F4.2 mag e_zmag ? rms uncertainty on zmag
103-105 A3 --- Tel Telescope
--------------------------------------------------------------------------------
Note (1): No K-corrections have been applied.
Note that the PS1 observations have had any flux from previous reference
image removed through image subtraction (although note that no host object
can be seen at the location of PS1-10ahf) whereas the late time WHT and GS
observations have not.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Field Field
6- 16 A11 --- Name Supernova PS1 designation (PS1-NNAAA)
18- 25 F8.4 deg RAdeg Right ascension (J2000)
27- 34 F8.4 deg DEdeg Declination (J2000)
36- 40 F5.3 --- soft ?=- Probability that the object is classified
as the SNe type given in Typesoft column
(soft photometric classification code) (G1)
42- 44 A3 --- Typesoft Type from soft (2)
46- 50 F5.3 --- psnid ?=- Probability that the object is classified
as the SNe type given in Typepsnid column
(psnid photometric classification code) (G1)
52- 54 A3 --- Typepsnid Type from psnid (2)
56- 61 F6.3 mag rP1mag ?=- Peak rP1 magnitude
63- 67 F5.3 mag e_rP1mag ? rms uncertainty on peak rP1 magnitude
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Note (2): none of these objects met with the confidence restrictions placed upon
the photometric classifiers for identifying SNe (see Tables 4 and 6 for
objects that do), it can be seen here that a large number of these objects
were given some sort of tentative, photometric SNe classification.
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Byte-by-byte Description of file: tablea3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Field Field
6- 16 A11 --- Name Supernova PS1 designation (PS1-NNAAA)
18- 25 F8.4 deg RAdeg Right ascension (J2000)
27- 34 F8.4 deg DEdeg Declination (J2000)
36- 41 F6.3 mag rP1mag ?=- Peak rP1 magnitude
43- 47 F5.3 mag e_rP1mag ? rms uncertainty on peak rP1 magnitude
49- 53 A5 --- LC LC Status (1)
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Note (1): LC Status as follows:
INC = objects have incomplete light curves
VAR = objects have variable light curves with no obvious trend
FAINT = objects fall out of the magnitude range for spectroscopic or
reliable photometric classification
RED = no detections in the gP1- or rP1-band filters but showed a
faint peak in the iP1- and zP1-band filters, possibly as a
result of a single, energetic outburst such as an SN at high redshift
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Global notes:
Note (G1): soft and psnid photometric classification codes
(Sako et al., 2008AJ....135..348S 2008AJ....135..348S, Cat. J/AJ/135/348,
2011ApJ...738..162S 2011ApJ...738..162S, Cat. J/ApJ/738/162; Rodney & Tonry 2009ApJ...707.1064R 2009ApJ...707.1064R).
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 04-Sep-2015