J/ApJ/878/71 ULXs with multiepoch Spitzer/IRAC obs. (Lau+, 2019)
Uncovering red and dusty ultraluminous X-ray sources with Spitzer.
Lau R.M., Heida M., Walton D.J., Kasliwal M.M., Adams S.M., Cody A.M.,
De K., Gehrz R.D., Furst F., Jencson J.E., Kennea J.A., Masci F.
<Astrophys. J., 878, 71 (2019)>
=2019ApJ...878...71L 2019ApJ...878...71L
ADC_Keywords: X-ray sources; Photometry, infrared; Magnitudes, absolute;
Galaxies, IR; Surveys; Active gal. nuclei; Stars, giant
Keywords: circumstellar matter ; dust, extinction ; infrared: stars;
stars: black hole ; stars: neutron ; supergiants
Abstract:
We present a mid-infrared (IR) sample study of nearby ultraluminous
X-ray sources (ULXs) using multiepoch observations with the Infrared
Array Camera (IRAC) on the Spitzer Space Telescope. Spitzer/IRAC
observations taken after 2014 were obtained as part of the Spitzer
Infrared Intensive Transients Survey. Our sample includes 96 ULXs
located within 10 Mpc. Of the 96 ULXs, 12 have candidate counterparts
consistent with absolute mid-IR magnitudes of supergiants, and 16
counterparts exceeded the mid-IR brightness of single supergiants and
are thus more consistent with star clusters or non-ULX background
active galactic nuclei. The supergiant candidate counterparts exhibit
a bimodal color distribution in a Spitzer/IRAC color-magnitude
diagram, where "red" and "'blue" ULXs fall in IRAC colors
[3.6]-[4.5]∼0.7 and [3.6]-[4.5]∼0.0, respectively. The mid-IR colors
and absolute magnitudes of four "red" and five "blue" ULXs are
consistent with those of supergiant B[e] (sgB[e]) and red supergiant
(RSG) stars, respectively. Although "blue," RSG-like mid-IR ULX
counterparts likely host RSG mass donors; we propose that "red"
counterparts are ULXs exhibiting the "B[e] phenomenon" rather than
hosts of sgB[e] mass donors. We show that the mid-IR excess from the
"red" ULXs is likely due to thermal emission from circumstellar or
circumbinary dust. Using dust as a probe for total mass, we estimate
mass-loss rates of dM/dt∼1x10-4M☉/yr in dust-forming outflows
of red ULXs. Based on the transient mid-IR behavior and its relatively
flat spectral index, α=-0.19±0.1, we suggest that the mid-IR
emission from Holmberg IX X-1 originates from a variable jet.
Description:
In order to search for mid-IR ultraluminous X-ray (ULX) counterparts,
we utilized imaging data taken in the SPitzer InfraRed Intensive
Transient Survey (SPIRITS; Kasliwal+ 2017, J/ApJ/839/88) as well as
archival Spitzer Post Basic Calibrated (PBCD) imaging data from the
Spitzer Heritage Archive.
SPIRITS is a program that has been going in since 2014 and has
been renewed for Spitzer Cycle 14 (until 2019 November 30).
Additionally, many of the nearby ULX host galaxies have previous
imaging observations with Spitzer from as long ago as 2004.
As part of SPIRITS, we performed follow-up ground-based near-IR J, H,
and/or Ks imaging observations with the Multi-object Spectrometer for
Infra-red Exploration (MOSFIRE) on Keck I, FourStar on the Magellan
6.5m Baade Telescope, and the Wide Field Infrared Camera (WIRC) on the
Palomar 200 inch Telescope.
In a dedicated IR ULX follow-up program, the ULX Holmberg II X-1 was
observed with the NIRC2 instrument on Keck II with the laser guide
star adaptive optics (LGSAO) system on 2018 November 28. See Section 2.4.
In order to investigate possible correlations between mid-IR/X-ray
variability in ULXs from our Spitzer DDT program (PID-13163), we
conducted contemporaneous observations with the X-ray Telescope (XRT)
on the Neil Gehrels Swift Observatory of five ULXs: Holmberg II X-1,
Holmberg IX X-1, NGC 925 ULX1, NGC 925 ULX2, and NGC 253 ULX1.
See Section 2.5.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 154 96 ULX candidate sample
table2.dat 100 433 Spitzer/IRAC observations of candidate stellar
mid-IR ULX counterparts
table4.dat 112 31 Candidate star clusters, AGN, and background galaxy
ULX counterparts
table5.dat 94 149 Spitzer/IRAC mid-IR non-detections of ULXs
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See also:
B/swift : Swift Master Catalog (HEASARC, 2004-)
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
IX/57 : The Chandra Source Catalog (CSC), Release 2.0 (Evans+, 2019)
J/A+AS/142/425 : BVRI photometry of 6 galaxies (Drozdovsky+, 2000)
J/ApJ/560/675 : Chandra X-ray point sources in Cen A (Kraft+, 2001)
J/ApJS/154/519 : Properties of ultraluminous X-ray candidates (Swartz+, 2004)
J/ApJ/601/735 : M51 luminous X-ray sources (Terashima+, 2004)
J/ApJS/157/59 : Ultraluminous X-ray sources in nearby galaxies (Liu+, 2005)
J/A+A/429/1125 : Catalog of Ultraluminous X-ray sources (Liu+, 2005)
J/AJ/132/2268 : SAGE calibration stars (Meixner+, 2006)
J/ApJ/649/730 : ULX population in nearby galaxies from XMM (Winter+, 2006)
J/ApJS/173/185 : GALEX UV atlas of nearby galaxies (Gil de Paz+, 2007)
J/AJ/138/1003 : IR photometry of massive LMC stars (Bonanos+, 2009)
J/ApJ/705/1533 : NGC 5128 globular clusters (Chattopadhyay+, 2009)
J/AJ/138/332 : LEDA CMD/tip of the red giant branch (Jacobs+, 2009)
J/AJ/140/1475 : ARAUCARIA: NGC 7793 Cepheids (Pietrzynski+, 2010)
J/ApJS/192/10 : Chandra ACIS survey in 383 nearby galaxies. I. (Liu, 2011)
J/ApJ/733/124 : Cepheids in M101 observed with HST (Shappee+, 2011)
J/ApJ/741/49 : ULX candidates in nearby galaxies (Swartz+, 2011)
J/MNRAS/416/1844 : 2XMM ultraluminous X-ray source candidates (Walton+, 2011)
J/ApJ/756/27 : Classification of sources from 2XMMi-DR3 (Lin+, 2012)
J/MNRAS/419/2095 : HMXBs in nearby galaxies (Mineo+, 2012)
J/AJ/146/86 : Cosmicflows-2 catalog (Tully+, 2013)
J/MNRAS/446/470 : ULX candidates in luminous IR galaxies (Luangtip+, 2015)
J/A+A/587/A121 : The IR source catalog of nearby galaxies (Williams+, 2016)
J/ApJS/225/1 : SpIES: the Spitzer IRAC Equatorial Survey (Timlin+, 2016)
J/ApJ/836/64 : Luminous variable stars in M31 & M33. IV. (Humphreys+, 2017)
J/ApJ/839/88 : 14 unusual IR transients with Spitzer (Kasliwal+, 2017)
http://sha.ipac.caltech.edu/applications/Spitzer/SHA/ : Spitzer Heritage
Archive
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Gal Host galaxy name
13 A1 --- f_Gal [Y/N] Galaxy included in the SPitzer InfraRed
Intensive Transient Survey (SPIRITS;
Kasliwal+ 2017, J/ApJ/839/88)
15- 43 A29 --- Name ULX name used in this work
45- 74 A30 --- OName Other name
76- 77 I2 h RAh X-ray hour of right ascension (J2000)
79- 80 I2 min RAm X-ray minute of right ascension (J2000)
82- 86 F5.2 s RAs X-ray second of right ascension (J2000)
88 A1 --- DE- X-ray sign of declination (J2000)
89- 90 I2 deg DEd X-ray degree of declination (J2000)
92- 93 I2 arcmin DEm X-ray arcminute of declination (J2000)
95- 98 F4.1 arcsec DEs X-ray arcsecond of declination (J2000)
100-102 F3.1 arcsec ePos [0.3/2.3] 2σ X-ray positional uncertainty
104-108 F5.2 Mpc Dist [1.88/14.19] Adopted distance to the ULX
110-113 F4.2 Mpc e_Dist [0/3.18] Dist uncertainty
115 A1 --- r_Dist Distance reference (1)
117-134 A18 --- Auth Author of the reference for the X-ray position
136-154 A19 --- BibCode Bibcode of the reference for the X-ray position
--------------------------------------------------------------------------------
Note (1): The distance references are as follows:
A = Gieren et al. (2005ApJ...628..695G 2005ApJ...628..695G)
B = Tully et al. (2013AJ....146...86T 2013AJ....146...86T -- Cosmicflows-2 catalog, J/AJ/146/86)
C = Dalcanton et al. (2009ApJS..183...67D 2009ApJS..183...67D)
D = Pietrzynski et al. (2010, J/AJ/140/1475)
E = McLean et al. (2010SPIE.7735E..1EM)
F = Tully et al. (2009AJ....138..323T 2009AJ....138..323T)
G = Jacobs et al. (2009, J/AJ/138/332)
H = Karachentsev et al. (2002A&A...383..125K 2002A&A...383..125K)
I = Tully (1988Nearb......221T 1988Nearb......221T)
J = Shappee & Stanek (2011, J/ApJ/733/124)
K = Drozdovsky & Karachentsev (2000, J/A+AS/142/425)
L = Poznanski et al. (2009ApJ...694.1067P 2009ApJ...694.1067P)
M = Tikhonov et al. (2015AstL...41..239T 2015AstL...41..239T)
N = Springob et al. (2009ApJS..182..474S 2009ApJS..182..474S)
O = Olivares et al. (2010ApJ...715..833O 2010ApJ...715..833O)
P = Willick et al. (1997ApJS..109..333W 1997ApJS..109..333W, VII/198)
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Gal Host Galaxy
13- 27 A15 --- Name ULX Counterpart name, including host
29- 36 F8.2 d MJD Modified Julian Date (JD-2400000.5)
38- 38 I1 --- IRAC [1/2] IRAC Channel (3.6 or 4.5um)
40- 40 A1 --- l_Flux Limit flag on Flux
42- 47 F6.2 uJy Flux [1.3/277.3] Flux in IRAC channel
49- 52 F4.2 uJy e_Flux [0.2/5.5]? Uncertainty in Flux
54- 54 A1 --- l_mag Limit flag on omag
56- 60 F5.2 mag mag [14.67/20.5] Vega magnitude in IRAC channel
62- 65 F4.2 mag e_mag [0.01/0.3]? Uncertainty in mag
67- 67 A1 --- l_MAG Limit flag on AbsMag
69- 74 F6.2 mag MAG [-13.21/-7.3] Absolute magnitude in IRAC channel
76- 79 F4.2 mag e_MAG [0.01/0.3]? Uncertainty in MAG
81- 84 F4.2 mag ZP [0.03/0.4]? Zeropoint uncertainty error in MAG
86- 94 A9 --- PI Principle Investigator of Observation
96-100 I5 --- PID [60/90240] Program identifier of Observation
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Gal Host Galaxy
12- 40 A29 --- Name ULX Counterpart name, including host
42- 49 F8.2 d MJD Modified Julian Date (JD-2400000.5)
51- 51 I1 --- IRAC [1/2] IRAC Channel
53- 59 F7.2 uJy Flux [40.23/2069.82] Flux in IRAC channel
61- 66 F6.2 uJy e_Flux [0.73/140.18] Uncertainty in Flux
68- 72 F5.2 mag mag [12.44/17.11] Vega magnitude in IRAC channel
74- 78 F5.3 mag e_mag [0.001/0.127] Uncertainty in mag
80- 85 F6.2 mag MAG [-16.9/-12.21] Absolute magnitude in IRAC channel
87- 91 F5.3 mag e_MAG [0.001/0.127] Uncertainty in MAG
93- 96 F4.2 mag ZP [0.03/0.4] Zeropoint uncertainty error in MAG
98-106 A9 --- PI Principle Investigator of Observation
108-112 I5 --- PID [60/80196] Program identifier of Observation
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Gal Host Galaxy
11- 39 A29 --- Name ULX Counterpart name, including host
41 A1 --- n_Name [a] Note on Name (1)
43- 50 F8.2 d MJD Modified Julian Date (JD-2400000.5)
52- 52 I1 --- IRAC [1/2] IRAC Channel
54- 54 A1 --- l_Flux Limit flag on Flux
56- 61 F6.2 uJy Flux [0.82/984.8] Flux in IRAC channel
63- 63 A1 --- l_mag Limit flag on mag
65- 69 F5.2 mag mag [13.0/21.13] Vega magnitude in IRAC channel
71- 71 A1 --- l_MAG Limit flag on MAG
73- 78 F6.2 mag MAG [-16.8/-6.96] Absolute magnitude in IRAC channel
80- 88 A9 --- PI Principle Investigator of Observation
90- 94 I5 --- PID [69/80196] Program identifier of Observation
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Note (1): [LB2005] NGC 4631 ULX1 and [LB2005] NGC 891 ULX3 are not included in
the final ULX sample (Table 1): positional uncertainties greater than 7".
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 03-Dec-2020