J/ApJ/839/88 14 unusual IR transients with Spitzer (SPRITEs) (Kasliwal+, 2017)
SPIRITS: uncovering unusual infrared transients with Spitzer.
Kasliwal M.M., Bally J., Masci F., Cody A.M., Bond H.E., Jencson J.E.,
Tinyanont S., Cao Yi, Contreras C., Dykhoff D.A., Amodeo S., Armus L.,
Boyer M., Cantiello M., Carlon R.L., Cass A.C., Cook D., Corgan D.T.,
Faella J., Fox O.D., Green W., Gehrz R.D., Helou G., Hsiao E.,
Johansson J., Khan R.M., Lau R.M., Langer N., Levesque E., Milne P.,
Mohamed S., Morrell N., Monson A., Moore A., Ofek E.O., O' Sullivan D.,
Parthasarathy M., Perez A., Perley D.A., Phillips M., Prince T.A.,
Shenoy D., Smith N., Surace J., Van Dyk S.D., Whitelock P.A., Williams R.
<Astrophys. J., 839, 88 (2017)>
=2017ApJ...839...88K 2017ApJ...839...88K
ADC_Keywords: Photometry, infrared ; Galaxies, nearby ; Surveys ; Photometry, RI
Keywords: infrared: general ; novae, cataclysmic variables ;
stars: AGB and post-AGB ; stars: mass-loss ; supernovae: general ;
surveys
Abstract:
We present an ongoing, five-year systematic search for extragalactic
infrared transients, dubbed SPIRITS-SPitzer InfraRed Intensive
Transients Survey. In the first year, using Spitzer/IRAC, we searched
190 nearby galaxies with cadence baselines of one month and six
months. We discovered over 1958 variables and 43 transients. Here, we
describe the survey design and highlight 14 unusual infrared
transients with no optical counterparts to deep limits, which we refer
to as SPRITEs (eSPecially Red Intermediate-luminosity Transient
Events). SPRITEs are in the infrared luminosity gap between novae and
supernovae, with [4.5] absolute magnitudes between -11 and -14
(Vega-mag) and [3.6]-[4.5] colors between 0.3mag and 1.6mag. The
photometric evolution of SPRITEs is diverse, ranging from <0.1mag/yr
to >7mag/yr. SPRITEs occur in star-forming galaxies. We present an
in-depth study of one of them, SPIRITS 14ajc in Messier 83, which
shows shock-excited molecular hydrogen emission. This shock may have
been triggered by the dynamic decay of a non-hierarchical system of
massive stars that led to either the formation of a binary or a
protostellar merger.
Description:
The SPitzer InfraRed Intensive Transients Survey (SPIRITS) survey uses
the IRAC instrument (FoV 5'x5') on board the warm Spitzer telescope to
search for IR transients at 3.6um ([3.6]) and 4.5um ([4.5]).
SPIRITS is a five-year survey from 2014 to 2018
(Kasliwal+ 2013sptz.prop10136K, 2016sptz.prop13053K).
We are undertaking concomitant ground-based surveys to monitor the
SPIRITS galaxy sample in the near-IR and the optical at roughly a
monthly cadence. At the University of Minnesota's Mt. Lemmon Observing
Facility (MLOF), we use the three-channel Two Micron All Sky Survey
cameras mounted on the 1.52m IR telescope. At Las Campanas, we
undertake near-IR monitoring with the Retrocam on Dupont 100 inch
telescope and optical monitoring using the CCD on the Swope 40 inch
telescope. At Palomar, we use the Samuel Oschin 48 inch (primarily
gr-band) and Palomar 60 inch telescopes (gri-bands) for optical
monitoring. Using the LCOGT network, we obtain additional optical
monitoring in gri-bands. In addition, a follow-up of discovered
transients was undertaken by a myriad of facilities including Keck,
Magellan, Palomar 200 inch, SALT, and RATIR.
Following non-detections from the ground, we were able to set even
deeper magnitude limits for two transients based on a small HST
Director's Discretionary program (GO/DD-13935, PI H. Bond). We imaged
SPIRITS 14aje (in M101) and SPIRITS 14axa (in M81) with the Wide Field
Camera 3 (WFC3) in 2014 September.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 56 194 SPitzer InfraRed Intensive Transients Survey
(SPIRITS) sample of galaxies
table2.dat 75 14 eSPecially Red Intermediate-luminosity Transient
Events (SPRITEs): coordinates and host galaxies
table3.dat 93 14 Light curve properties of SPRITEs
table4.dat 59 762 Follow-up photometry
table5.dat 40 320 Spitzer photometry of all SPRITEs
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See also:
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/AJ/138/332 : LEDA CMD/tip of the red giant branch (Jacobs+, 2009)
J/ApJ/705/1364 : MIR catalog of point sources in M33 (Thompson+, 2009)
J/PASP/122/1397 : Spitzer Survey of Stellar Structure in Gal. (Sheth+, 2010)
J/ApJ/778/L19 : SN 2011dh (type IIb) 3.6 and 4.5um LCs (Helou+, 2013)
J/AJ/146/86 : Cosmicflows-2 catalog (Tully+, 2013)
J/AJ/147/82 : Monitoring of disk-bearing stars in NGC 2264 (Cody+, 2014)
J/A+A/579/A130 : Near-IR BN/KL outflow images (Bally+, 2015)
J/ApJS/216/10 : DUSTiNGS. I. The Good Source Catalog (Boyer+, 2015)
J/ApJ/834/107 : Follow-up photometry of M101 OT2015-1 (Blagorodnova+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 21 A21 --- Host Name of the target galaxy
23- 30 A8 --- PGC PGC Number (Paturel+, 1989, VII/119;
superseded by VII/237)
32- 33 I2 h RAh Hour of Right Ascension (J2000)
35- 36 I2 min RAm Minute of Right Ascension (J2000)
38- 43 F6.3 s RAs Second of Right Ascension (J2000)
45- 45 A1 --- DE- Sign of the Declination (J2000)
46- 47 I2 deg DEd Degree of Declination (J2000)
49- 50 I2 arcmin DEm Arcminute of Declination (J2000)
52- 56 F5.2 arcsec DEs Arcsecond of Declination (J2000)
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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- 7 A7 --- --- [SPIRITS]
9- 13 A5 --- SPIRITS SPRITEs Name (YYaaa)
15- 16 I2 h RAh Hour of Right Ascension (J2000)
18- 19 I2 min RAm Minute of Right Ascension (J2000)
21- 25 F5.2 s RAs Second of Right Ascension (J2000)
27- 27 A1 --- DE- Sign of the Declination (J2000)
28- 29 I2 deg DEd Degree of Declination (J2000)
31- 32 I2 arcmin DEm Arcminute of Declination (J2000)
34- 37 F4.1 arcsec DEs Arcsecond of Declination (J2000)
39- 49 A11 --- Host Host Galaxy
51- 55 F5.2 mag DM [27.5/29.4] Distance Modulus
57- 75 A19 --- r_DM Bibcode of the reference for DM
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- --- [SPIRITS]
9- 13 A5 --- SPIRITS SPRITEs Name (YYaaa)
15- 21 F7.1 d PkT3.6 3.6um Peak Time, MJD
23- 27 F5.1 mag PkMag3.6 [-12.5/-10.8] 3.6um Peak absolute magnitude
29- 35 F7.1 d PkT4.5 4.5um Peak Time, MJD
37- 41 F5.1 mag PkMag4.5 [-13.7/-11.2] 4.5um Peak absolute magnitude
43- 49 F7.1 d PkTCol Color (3.6um-4.5um) Peak Time, MJD
51- 53 F3.1 mag PkMagCol [0.3/1.6] Color (3.6um-4.5um) Peak magnitude
55- 60 F6.2 mag PrMag3.6 [-11.4/-7.9]? Progenitor limit, 3.6um,
absolute mag
62- 67 F6.2 mag PrMag4.5 [-11.7/-9.3]? Progenitor limit, 4.5um,
absolute mag
69- 71 F3.1 yr LS3.6 [0.1/5.6]? Lifespan, 3.6um
73- 73 A1 --- l_Evo3.6 Limit flag on LS-3.6
74- 78 F5.1 mag/yr Evo3.6 [-32.2/2.4]? Evolution, 3.6um
80- 82 F3.1 yr LS4.5 [0.1/7.1]? Lifespan, 4.5um
84- 84 A1 --- l_Evo4.5 Limit flag on LS-4.5
85- 88 F4.1 mag/yr Evo4.5 [-6.2/7.3]? Evolution, 4.5um
90- 93 A4 --- Speed Speed: Slow or Fast
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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- 7 A7 --- --- [SPIRITS]
9- 13 A5 --- SPIRITS SPRITEs Name (YYaaa)
15- 18 I4 yr Obs.Y Observation year (1)
20- 21 I2 --- Obs.M ? Observation month (1)
23- 27 F5.2 d Obs.D ? Observational day (1)
29- 31 I3 --- Nstack [10/157]? Number of stacked images (1)
33- 40 A8 --- Tel Telescope (2)
42- 49 A8 --- Instr Instrument (3)
51- 52 A2 --- Filt Filter (R, I, g, r, i, J, H or Ks)
54- 54 A1 --- l_mag Limit flag on mag
55- 59 F5.2 mag mag [12.8/26.5] Observation magnitude in Filt
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Note (1): Observation dates given both as individual (nightly) values and
as stacked values over the year (Obs.Y), with no Obs.M or Obs.D recorded
in the table. The number of stacked images is given as Nstack.
Note (2): Telescope used as follows:
HST = Hubble Space Telescope;
P48 = Samuel Oschin 48-inch, Palomar observatory;
Keck = Keck Observatory;
MLOF = 1.52m IR telescope, Mt Lemmon Observing Facility;
Swope = Swope 40-inch telescope, Las Companas;
duPont = Dupont 100-inch telescope, Las Campanas;
LCOGT-1m = LCOGT-1m telescopes.
Note (3): Instrument used as follows:
CCD = CCD on Swope 40-inch;
SBIG = LCOGT-1m SBIG camera;
WFC3 = HST Wide Field Camera 3;
iPTF = Intermediate Palomar Transient Factory, Palomar;
2MASS = Three-channel Two Micron All Sky Survey cameras;
DEIMOS = DEep Imaging Multi-Object Spectrograph, Keck;
MOSFIRE = MOSFIRE, NIR multi-object spectrograph, Keck;
Retrocam = Retrocam on Dupont 100-inch.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- --- [SPIRITS]
9- 13 A5 --- SPIRITS SPRITEs Name (YYaaa)
15- 22 F8.2 d MJD Observation date, JD-2400000.5
24- 28 A5 --- Filt Spitzer Filter ("[3.6]" or "[4.5]")
30- 30 A1 --- l_mag Limit flag on mag
31- 35 F5.2 mag mag [14.2/29.6] Observation magnitude in Filt
37- 40 F4.2 mag e_mag [0/0.06]? Uncertainty in mag
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 23-Nov-2017