J/ApJ/928/158 HST imaging and light curves of 21 SPIRITS variables (Bond+, 2022)
Hubble Space Telescope imaging of luminous extragalactic infrared transients and
variables from the SPitzer InfraRed Intensive Transients Survey.
Bond H.E., Jencson J.E., Whitelock P.A., Adams S.M., Bally J., Cody A.M.,
Gehrz R.D., Kasliwal M.M., Masci F.J.
<Astrophys. J., 928, 158 (2022)>
=2022ApJ...928..158B 2022ApJ...928..158B
ADC_Keywords: Transient; Stars, variable; Infrared sources; Photometry, HST;
Optical
Keywords: Supernovae ; Transient sources ; Classical novae ; Variable stars ;
Infrared sources ; OH/IR stars ; Red supergiant stars ;
Luminous blue variable stars
Abstract:
The SPitzer InfraRed Intensive Transients Survey (SPIRITS) searched
for luminous infrared (IR) transients and variables in nearly
200 nearby galaxies from 2014 to 2019, using the warm Spitzer
telescope at 3.6 and 4.5µm. Among the SPIRITS variables are
IR-bright objects that are undetected in ground-based optical surveys.
We classify them as (1) transients, (2) periodic variables, and
(3) irregular variables. The transients include eSPecially Red
Intermediate-luminosity Transient Events (SPRITEs), having maximum
luminosities fainter than supernovae, red IR colors, and a wide range
of outburst durations (days to years). Here we report deep optical and
near-IR imaging with the Hubble Space Telescope (HST) of 21 SPIRITS
variables. They were initially considered SPRITE transients, but many
eventually proved instead to be periodic or irregular variables as
more data were collected. HST images show most of these cool and dusty
variables are associated with star-forming regions in late-type
galaxies, implying an origin in massive stars. Two SPRITEs lacked
optical progenitors in deep preoutburst HST images; however, one was
detected during eruption at J and H, indicating a dusty object with an
effective temperature of ∼1050K. One faint SPRITE turned out to be a
dusty classical nova. About half the HST targets proved to be periodic
variables, with pulsation periods of 670-2160d; they are likely dusty
asymptotic-giant-branch (AGB) stars with masses of ∼5-10M☉. A
few of them were warm enough to be detected in deep HST frames, but
most are too cool. Out of six irregular variables, two were red
supergiants with optical counterparts in HST images; four were too
enshrouded for HST detection.
Description:
In 2014, our team started a systematic search for luminous IR
transients and variables in nearby galaxies, called the SPitzer
InfraRed Intensive Transients Survey (SPIRITS). Our survey used the
Infrared Array Camera (IRAC) on the warm Spitzer Space Telescope to
search for variable extragalactic objects at wavelengths of 3.6 and
4.5um. Full details of the SPIRITS survey and initial discoveries are
presented in Kasliwal+ 2017 (J/ApJ/839/88), and updated overviews are
given by Jencson+ (2019, J/ApJ/886/40 and 2020PhDT.........1J 2020PhDT.........1J).
For the infrared transients and SPRITEs, we also include optical
constraints from wide-field, untargeted surveys, namely, the
intermediate Palomar Transient Factory (iPTF) and the Asteroid
Terrestrial-impact Last Alert System (ATLAS). See Section 6.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 48 22 HST Wide Field Camera 3 observing log
table2.dat 67 22 HST targets and light-curve classifications
fig1.dat 50 1363 Spitzer IRAC, ATLAS and iPTF light curves
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See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
II/342 : Hubble Source Catalog (V1 and V2) (Whitmore+, 2016)
J/A+A/442/281 : Late-type giants BVRIJHKL & Teff calib. (Kucinskas+, 2005)
J/AcA/59/239 : VI LCs of LMC long-period variables (Soszynski+, 2009)
J/ApJS/187/275 : Photometric histories of recurrent novae (Schaefer, 2010)
J/ApJ/727/53 : Red supergiant stars in the LMC. I. (Yang+, 2011)
J/AJ/146/86 : Cosmicflows-2 catalog (Tully+, 2013)
J/ApJ/799/215 : 26 type II-Plateau supernovae parameters (Pejcha+, 2015)
J/AJ/152/50 : Cosmicflows-3 catalog (CF3) (Tully+, 2016)
J/ApJ/834/107 : Follow-up photometry of M101 OT2015-1 (Blagorodnova+, 2017)
J/ApJ/839/88 : IR transients with Spitzer (SPRITEs) (Kasliwal+, 2017)
J/ApJ/834/196 : Galactic novae with m≤10 from 1900 to 2015 (Shafter, 2017)
J/A+A/632/L6 : AT 2018hso light curves and spectra (Cai+, 2019)
J/ApJ/877/49 : DUSTiNGS. V. 3.6 and 4.5um light curves (Goldman+, 2019)
J/ApJ/886/40 : Most luminous SPIRITS IR transients (Jencson+, 2019)
J/ApJ/877/110 : SPIRITS cat. of IR long period var. (Karambelkar+, 2019)
J/MNRAS/483/5150 : Variables in NGC3109 dwarf irregular galaxy (Menzies+, 2019)
J/A+A/630/A75 : Six luminous red novae photometry (Pastorello+, 2019)
J/ApJS/241/38 : A comprehensive analysis of Spitzer SNe (Szalai+, 2019)
J/A+A/637/A20 : AT 2019abn: multi-wavelength observations (Williams+, 2020)
J/A+A/654/A157 : 5 ILRTs light curves and spectra (Cai+, 2021)
J/ApJ/912/19 : Follow-up phot. & sp. of 12 PGIR novae (De+, 2021)
J/AJ/162/183 : IR spectra of V838 Monocerotis with SOFIA (Woodward+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- SPIRITS SPIRITS name
7 A1 --- f_SPIRITS Flag on SPIRITS (1)
9- 16 A8 --- Gal Host galaxy name
18- 27 A10 "Y/M/D" Date Observation date
29- 33 I5 --- PropID [13935/14892] Program ID
35- 38 I4 s ExpF814W [584/1659]? F814W total exposure time
40- 43 I4 s ExpF110W [484/2385]? F110W total exposure time
45- 48 I4 s ExpF160W [155/2385] F160W total exposure time
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Note (1): Flag as follows:
e = SPIRITS 16tn has been analyzed in detail by Jencson+ (2018ApJ...863...20J 2018ApJ...863...20J),
and interpreted as a heavily obscured core-collapse SN. Tabulated here
for completeness, but not discussed in this paper.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Gal Host galaxy name
10- 14 F5.2 mag m-M [27.34/29.82]? Galaxy distance modulus
16- 19 F4.2 mag e_m-M [0.02/0.45]? m-M uncertainty
21 A1 --- r_m-M Distance moduli reference (2)
23- 27 A5 --- SPIRITS SPIRITS name
29- 30 I2 h RAh Hour of right ascension (J2000)
32- 33 I2 min RAm Minute of right ascension (J2000)
35- 39 F5.2 s RAs Second of right ascension (J2000)
41 A1 --- DE- Sign of declination (J2000)
42- 43 I2 deg DEd Degree of declination (J2000)
45- 46 I2 arcmin DEm Arcminute of declination (J2000)
48- 51 F4.1 arcsec DEs Arcsecond of declination (J2000)
53- 65 A13 --- Class Light-curve classification
67 A1 --- f_Class b=Probably a classical nova; see Section 6.3
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Note (2): Reference as follows:
a = Tully et al. (2013, J/AJ/146/86)
b = Jang & Lee (2017ApJ...836...74J 2017ApJ...836...74J)
c = Pejcha & Prieto (2015, J/ApJ/799/215)
d = Tully et al. (2016, J/AJ/152/50)
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Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- SPIRITS SPIRITS designation
7- 15 F9.3 d MJD [52949/59229.2] Modified Julian date
(JD-2400000.5)
17- 28 A12 --- Tel Telescope and instrument ("Spitzer/IRAC", "iPTF"
or "ATLAS")
30- 36 A7 --- Band Photometric band
38 A1 --- l_mag Limit flag on mag (1)
39- 43 F5.2 mag mag [13.8/22.8] Apparent magnitude in Band (2)
47- 50 F4.2 mag e_mag [0.01/0.7]? 1-sigma uncertainty in mag
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Note (1): Limiting magnitude for a non-detection
Note (2): Vega magnitudes for Spitzer/IRAC, AB magnitudes for iPTF and ATLAS
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 01-Mar-2024