J/ApJS/273/5 T-ReX: the Tarantula-Revealed by X-rays (Townsley+, 2024)
T-ReX: the Tarantula-Revealed by X-rays.
Townsley L.K., Broos P.S., Povich M.S.
<Astrophys. J. Suppl. Ser., 273, 5 (2024)>
=2024ApJS..273....5T 2024ApJS..273....5T
ADC_Keywords: Star Forming Region; X-ray sources; Cross identifications; YSOs;
Optical; Infrared; Pulsars; Local group
Keywords: H II regions ; High energy astrophysics ; Early-type stars ;
Star formation ; Interstellar medium ; Superbubbles
Abstract:
The Tarantula Nebula (30 Doradus, 30 Dor) is the most important
star-forming complex in the Local Group, offering a microscope on
starburst astrophysics. At its heart lies the exceptionally rich young
stellar cluster R136, containing the most massive stars known. Stellar
winds and supernovae have carved 30 Dor into an amazing display of
arcs, pillars, and bubbles. We present first results and advanced
data-processing products from the 2 Ms Chandra X-ray Visionary
Project, "The Tarantula-Revealed by X-rays" (T-ReX). The 3615 point
sources in the T-ReX catalog include massive stars, compact objects,
binaries, bright pre-main-sequence stars, and compact young stellar
(sub)clusters in 30 Dor. After removing point sources and excluding
the exceptionally bright supernova remnant N157B (30 Dor B), the
global diffuse X-ray maps reveal hot plasma structures resolved at
1-10pc scales, with an absorption-corrected total-band (0.5-7keV)
X-ray luminosity of 2.110x1037erg/s. Spatially resolved spectral
modeling provides evidence for emission lines enhanced by
charge-exchange processes at the interfaces. We identify a candidate
for the oldest X-ray pulsar detected to date in 30 Dor, PSR J0538-6902,
inside a newly resolved arcuate X-ray wind nebula, the Manta Ray. The
long temporal baseline of T-ReX allowed monitoring of dozens of
massive stars, several showing periodic variability tied to binary
orbital periods, and captured strong flares from at least three
low-mass Galactic foreground stars.
Description:
"The Tarantula-Revealed by X-rays" (T-ReX) obtained 51 Chandra imaging
observations, using the four ACIS-I detectors plus the two central
ACIS-S detectors, with an aimpoint near the rich young stellar cluster
R136 over the period 2014 May 3 through 2016 January 22 (Table 1).
Including three archival observations of 30 Dor from 2006 January
brings the total exposure time to 2.05Ms. The exposure map for all
54 observations, with detected point sources overlaid
(see Section 2.3), is presented in Figure 1.
Identifying optical-infrared (OIR) counterparts to Chandra sources
("matching" X-ray and OIR catalogs) is often a challenging task. See
Appendix A for explanations.
Objects:
-----------------------------------------------------------
RA (ICRS) DE Designation(s)
-----------------------------------------------------------
05 38 35.99 -69 05 11.0 Tarantula = NAME 30 Dor Nebula
-----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 97 54 Log of Chandra observations
table2.dat 560 3615 "The Tarantula-Revealed by X-rays" (T-ReX) X-ray
source properties
table5.dat 237 106 Candidate and known massive stars with T-ReX
detections
table7.dat 169 238 Counterparts to X-ray sources beyond the massive
stellar population
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Description of files:
trexxrayproperties.fits is the original FITS file as provided in the paper
for Table 2.
See also:
B/chandra : The Chandra Archive Log (CXC, 1999-2014)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
VII/233 : 2MASS All-Sky Extended Source Catalog (XSC) (IPAC/UMass, 2003-2006)
II/351 : VISTA Magellanic Survey (VMC) catalog (Cioni+, 2011)
II/375 : VISTA Magellanic Survey (VMC) catalog (YJKs) DR6 (Cioni+, 2011)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
J/AJ/126/539 : The Chandra Deep Fields North and South (Alexander+, 2003)
J/AJ/132/2268 : SAGE calibration stars (Meixner+, 2006)
J/AJ/132/866 : New M dwarfs in solar neighborhood (Riaz+, 2006)
J/AJ/131/2164 : X-ray sources in RMC 136 (Townsley+, 2006)
J/ApJS/169/353 : Chandra sources in M17 (Broos+, 2007)
J/ApJS/179/19 : CDFS survey: 2 Ms source catalogs (Luo+, 2008)
J/AJ/136/18 : LMC SAGE. New candidate YSOs (Whitney+, 2008)
J/ApJ/696/1278 : The extended star-forming environment of M17 (Povich+, 2009)
J/ApJ/708/1760 : Flux estimations of faint X-ray sources (Getman+, 2010)
J/ApJS/194/2 : Chandra Carina Complex Project (CCCP) catalog (Broos+, 2011)
J/A+A/530/A108 : VLT-FLAMES Tarantula Survey (Evans+, 2011)
J/ApJS/194/15 : CCCP: Carina's diffuse X-ray emission (Townsley+, 2011)
J/ApJS/209/32 : Probable young stars in the MYStIX project (Broos+, 2013)
J/A+A/558/A134 : VLT-FLAMES Tarantula Survey. 30 Dor stars (Doran+, 2013)
J/ApJ/787/108 : Age estimates for massive SFR stellar pop. (Getman+, 2014)
J/ApJS/213/1 : The MSFRs Omnibus X-ray Catalog (MOXC) (Townsley+, 2014)
J/A+A/564/A40 : VFTS. O-type stellar content of 30 Dor (Walborn+, 2014)
J/A+A/574/A13 : VFTS. B-type stars classification and RV (Evans+, 2015)
J/ApJS/222/11 : Hubble Tarantula Treasury Project (HTTP). III. (Sabbi+, 2016)
J/A+A/598/A85 : Disentangled spectra of R145 (Shenar+, 2017)
J/ApJ/864/136 : Massive SFRs multiwavelength study (Binder+, 2018)
J/ApJS/235/43 : The 2nd MSFRs Omnibus X-ray Catalog (MOXC2) (Townsley+, 2018)
J/ApJS/244/28 : The 3rd MSFRs Omnibus X-ray Catalog (MOXC3) (Townsley+, 2019)
J/ApJ/916/32 : X-ray superflares from PMS stars (Getman+, 2021)
J/ApJ/914/47 : ISS/NICER X-ray observations of eta Car (Kashi+, 2021)
J/AJ/162/153 : X-ray data of A,B-types, T-Tauri stars & YSOs (Nunez+, 2021)
J/ApJ/935/43 : X-ray Sources Towards 10 Open Clusters (Getman+, 2022)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- ObsID [5906/18750] Observation identifier
7- 20 A14 --- DOI DOI of dataset (link to Chandra X-ray center)
22- 31 A10 "Y/M/D" Date Start date of observation (UT)
33- 37 I5 s Exp [9826/93761] Exposure time (1)
39- 40 I2 h RAh Hour of right ascension (J2000) (2)
42- 43 I2 min RAm Minute of right ascension (J2000)
45- 49 F5.2 s RAs Second of right ascension (J2000)
51 A1 --- DE- Sign of declination (J2000) (2)
52- 53 I2 deg DEd Degree of declination (J2000) (2)
55- 56 I2 arcmin DEm Arcminute of declination (J2000)
58- 61 F4.1 arcsec DEs Arcsecond of declination (J2000)
63- 65 I3 deg Roll [3/357] Roll angle
67- 83 A17 --- TGAIN Abbreviated name of the ACIS time-dependent
gain file (3)
85- 90 F6.3 pix Xsky [-1.5/1.8] RA shift in SKY pixel
(1 SKY pixel=0.492") (4)
92- 97 F6.3 pix Ysky [-2/1.7] DE shift in SKY pixel
(1 SKY pixel=0.492") (4)
--------------------------------------------------------------------------------
Note (1): Exposure times are the net usable times after various filtering
steps are applied in the data reduction process. No exposure time
needed to be removed during periods of high instrumental background.
The time variability of the ACIS background is discussed in Section 6.16.3
of the Chandra Proposers' Observatory Guide
(http://asc.harvard.edu/proposer/POG/) and in the ACIS Background
Memos at http://asc.harvard.edu/cal/Acis/Cal_prods/bkgrnd/current/
Note (2): The on-axis position is the time-averaged location of the optical
axis (CIAO parameters RA_PNT and DEC_PNT;
http://cxc.harvard.edu/ciao/faq/nomtargpnt.html).
Note (3): Abbreviated name of the ACIS Time-Dependent Gain file used for the
calibration of event energies,
e.g., "2002-02-01N6" = "acisD2002-02-01t_gainN0006.fits"
Note (4): The shift (in R.A. and decl.) applied to the ObsID's aspect file
(via the CIAO tool wcs_update) to achieve astrometric alignment,
expressed as (dx, dy) in the Chandra "SKY" coordinate system
(http://asc.harvard.edu/ciao/ahelp/coords.html);
1 SKY pixel = 0.492". Note that astrometric shifts are correlated in time.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- CXOU X-ray source name
(HHMMSS.ss+DDMMSS.s; J2000) (Name)
20- 27 A8 --- Label X-ray source name used within the project
(Label) (1)
--------------------------------------------------------------------------------
29- 37 F9.6 deg RAdeg [83.6/85.5] Right ascension (ICRS) (RAdeg)
(2)
39- 48 F10.6 deg DEdeg [-69.5/-68.7] Declination (ICRS) (DEdeg)
(2)
50- 57 F8.6 --- ePos [0.0014/2.2] 1σ error circle around
RAdeg,DEdeg (PosErr) (2)
59- 75 A17 --- PosType Algorithm used to estimate the position
(PosType) (2)
--------------------------------------------------------------------------------
77- 88 E12.6 --- no-m [0/0.01] Smallest of no-t, no-s, no-h and
no-v (ProbNoSrc_MostValid) (3)
90- 97 F8.6 --- no-t [0/0.6] Smallest p-value under the
no-source (0.5-7keV) null hypothesis among
the validation merges (ProbNoSrc_t) (3)
99- 106 F8.6 --- no-s [0/1]? Smallest p-value under the
no-source (0.5-2keV) null hypothesis among
the validation merges (ProbNoSrc_s) (3)
108- 115 F8.6 --- no-h [0/1]? Smallest p-value under the
no-source (2-7keV) null hypothesis among
the validation merges (ProbNoSrc_h) (3)
117- 124 F8.6 --- no-v [0/1]? Smallest p-value under the
no-source (4-7keV) null hypothesis among
the validation merges (ProbNoSrc_v) (3)
126 I1 --- Val? [0/1] 1="occasional" (1744 occurrences);
see Section 2.4 (IsOccasional) (3)
--------------------------------------------------------------------------------
128- 135 F8.6 --- KS_S [0/1]? The smallest p-value produced by
each source; see Section 2.5
(ProbKS_single)
137- 138 I2 --- NKS_S [0/54] Number of p-values compared to
produce KS_S (NKSsingle)
140- 147 F8.6 --- KS_M [0/1] p-value from a K-S test on the
combined events from all observations; the
null hypothesis is no variability on any
timescale (ProbKS_merge)
149- 156 F8.6 --- Chi2 [0/1] p-value from a Ξ2 test on the
single-ObsID measurements of PhotonFlux_t;
the null hypothesis is no inter-ObsID
variability (ProbChisq_PhotonFlux)
--------------------------------------------------------------------------------
158- 169 E12.6 s ExpNom [59161/2058941] Total exposure time in
merged ObsIDs (ExposureTimeNominal)
171- 178 F8.6 --- ExpFrac [0.5/1] Fraction of ExposureTimeNominal
that source was observed
(ExposureFraction) (4)
180- 187 F8.6 ct Ct [2.3e-05/0.26] 0.5-8keV rate in a 3x3 CCD
pixel cell in count/frame (possible pileup
bias if >0.05) (RateIn3x3Cell) (5)
189- 190 I2 --- Nobs [2/54] Total number of ObsIDs extracted
(NumObsIDs)
192- 193 I2 --- Nph [2/54] Number of ObsIDs merged to estimate
the photometric properties (NumMerged)
195- 202 F8.6 --- Fdis [0] Fraction of exposure discarded in the
merge (always "0") (MergeBias)
204- 212 F9.6 arcmin b_theta [0.001/20.8] Smallest off-axis angle for
the merged ObsIDs (Theta_Lo)
214- 222 F9.6 arcmin theta [0.4/20.8] Average off-axis angle for the
merged ObsIDs (Theta)
224- 232 F9.6 arcmin B_theta [0.49/20.8] Largest off-axis angle for the
merged ObsIDs (Theta_Hi)
234- 241 F8.6 --- PSFf [0.4/1] Average PSF fraction (at 1.5keV)
for the merged ObsIDs (PsfFraction)
243- 254 E12.6 --- Area [1.3/38733] Average aperture area for the
merged ObsIDs, in (0.492")2 (SrcArea)
256- 263 F8.6 --- aglowf [0/0.2]? Suspected afterglow fraction
(AfterglowFraction) (6)
265- 271 I7 ct Oct-t [6/1943580] Observed counts (0.5-8keV) in
the merged apertures (SrcCounts_t)
273- 279 I7 ct Oct-s [1/1219141] Observed counts (0.5-2keV) in
the merged apertures (SrcCounts_s)
281- 286 I6 ct Oct-h [0/724439] Observed counts (2-8keV) in the
merged apertures (SrcCounts_h)
288- 297 F10.6 --- BgScl [0.36/225] Scaling of the background
extraction (Broos+ 2010ApJ...714.1582B 2010ApJ...714.1582B,
Section 5.4) (BkgScaling)
299- 304 I6 ct bgct-t [132/216942] Observed counts (0.5-8keV) in
the merged background regions (BkgCounts_t)
306- 311 I6 ct bgct-s [36/133464] Observed counts (0.5-2keV) in
the merged background regions (BkgCounts_s)
313- 317 I5 ct bgct-h [30/83478] Observed counts (2-8keV) in the
merged background regions (BkgCounts_h)
319- 330 E12.6 ct Nct-t [-19/1.9e+06] Net counts (0.5-8keV) in the
merged apertures (NetCounts_t)
332- 343 E12.6 ct Nct-s [-35/1.2e+06] Net counts (0.5-2keV) in the
merged apertures (NetCounts_s)
345- 356 E12.6 ct Nct-h [-245/690066] Net counts (2-8keV) in the
merged apertures (NetCounts_h)
358- 369 E12.6 ct loNct-t [-20/1.9e+06] 1σ lower bound on Nct-t
(NetCountsLot) (7)
371- 382 E12.6 ct upNct-t [3.7/1.9e+06] 1σ upper bound on Nct-t
(NetCountsHit) (7)
384- 395 E12.6 ct loNct-s [-53.8/1.2e+06] 1σ lower bound on
Nct-s (NetCountsLos) (7)
397- 408 E12.6 ct upNct-s [2.3/1.2e+06] 1σ upper bound on Nct-s
(NetCountsHis) (7)
410- 421 E12.6 ct loNct-h [-66.7/689198]? 1σ lower bound on
Nct-h (NetCountsLoh) (7)
423- 434 E12.6 ct upNct-h [1.8/690934] 1σ upper bound on Nct-h
(NetCountsHih) (7)
436- 443 F8.4 cm2.ct/ph Area-t [54/244] Mean ARF value (0.5-8keV)
(MeanEffectiveArea_t) (8)
445- 452 F8.4 cm2.ct/ph Area-s [70/286] Mean ARF value (0.5-2keV)
(MeanEffectiveArea_s) (8)
454- 461 F8.4 cm2.ct/ph Area-h [50/234] Mean ARF value (2-8keV)
(MeanEffectiveArea_h) (8)
463- 474 E12.6 ph/cm2/s XFlx-t [-1.1e-07/0.02] Apparent photon flux
(0.5-8keV) (PhotonFlux_t) (9)
476- 487 E12.6 ph/cm2/s XFlx-s [-6e-07/0.006] Apparent photon flux
(0.5-2keV) (PhotonFlux_s) (9)
489- 500 E12.6 ph/cm2/s XFlx-h [-2.4e-06/0.007] Apparent photon flux
(2-8keV) (PhotonFlux_h) (9)
502- 507 F6.4 keV Emed-t [0.5/8]? Median energy, observed spectrum
(0.5-8keV) (MedianEnergy_t) (10)
509- 514 F6.4 keV Emed-s [0.5/2]? Median energy, observed spectrum
(0.5-2keV) (MedianEnergy_s) (10)
516- 521 F6.4 keV Emed-h [2/8]? Median energy, observed spectrum
(2-8keV) (MedianEnergy_h) (10)
523- 534 E12.6 mW/m2 EFlx-t [0/4.5e-11] Max(EnergyFlux_s,0) +
max(EnergyFlux_h,0) in erg/cm2/s
(EnergyFlux_t)
536- 547 E12.6 mW/m2 EFlx-s [3.4e-20/1.3e-11]? Apparent energy flux
(0.5-2keV) (EnergyFlux_s)
549- 560 E12.6 mW/m2 EFlx-h [2.2e-21/3.2e-11]? Apparent energy flux
(2-8keV) (EnergyFlux_h)
--------------------------------------------------------------------------------
Note (1): Source "labels" identify each source during data analysis, as the
source position (and thus the name) is subject to change.
Note (2): Source position, derived from the set of ObsIDs that minimized the
positional uncertainty (Broos+ 2010ApJ...714.1582B 2010ApJ...714.1582B, Section 6.2 and 7)
ACIS ObsIDs are shifted to align with our astrometric reference
catalog, composed of 20 stars chosen from VMC (Cioni+ 2011, II/375) and
2MASS (Skrutskie+ 2006, VII/233 - see II/246).
Note (3): Validity metrics, derived from a predefined set of ObsID combinations
(Townsley+ 2018, J/ApJS/235/43; Section 2.2.3)
"no-m" (ProbNoSrc_MostValid) is also defined in Broos+ 2010ApJ...714.1582B 2010ApJ...714.1582B,
Section 4.3; Weisskopf+ 2007ApJ...657.1026W 2007ApJ...657.1026W, Appendix A2
"Val?" (IsOccasional): flag indicating that the source validation failed
in all multi-ObsID merges; source validation comes from a single ObsID
(Townsley+ 2019, J/ApJS/244/28, Section 3.1).
Note (4): Due to dithering over inactive portions of the focal plane, a
Chandra source often is not observed during some fraction of the
nominal exposure time (http://cxc.harvard.edu/ciao/why/dither.html).
We report here the CIAO quantity "FRACEXPO" produced by the tool mkarf.
Note (5): The source properties in this table are not corrected for pileup
effects. "Ct" (RateIn3x3Cell) is an estimate of the observed count rate
falling on an event detection cell of size 3x3 ACIS pixels, centered
on the source position. When RateIn3x3Cell>0.05 (units of counts/frame),
the reported source properties may be biased by pileup effects.
See Section 2.6 for a list of source extractions confirmed to have
significant pileup.
Note (6): Some background events arising from an instrumental effect known
as "afterglow" (http://cxc.harvard.edu/ciao/why/afterglow.html) may
contaminate the source extractions. After extraction, we attempt to
identify afterglow events using the AE tool aeafterglowreport, and
report the fraction of extracted events attributed to afterglow; see
the AE manual.
Note (7): Confidence intervals (68%) for the NetCounts quantities are estimated
by the CIAO tool aprates (http://asc.harvard.edu/ciao/ahelp/aprates.html).
Note (8): The ancillary response file (ARF) in ACIS data analysis represents
both the effective area of the observatory and the fraction of the
observation time for which data were actually collected for the source
(column "ExpFrac" (ExposureFraction)).
Note (9): "XFlx"="Nct"/"Area"/"ExpNom"
(PhotonFlux=NetCounts/MeanEffectiveArea/ExposureTimeNominal);
Broos+ 2010ApJ...714.1582B 2010ApJ...714.1582B, Section 7.4.
"EFlx"="1.602x10-9erg/keV*"XFlx"*"Emed"
(EnergyFlux=1.602x10-9(units of erg/keV)*PhotonFlux*MedianEnergy);
Getman+ 2010, J/ApJ/708/1760; Section 2.2. Because MeanEffectiveArea
depends on the shape of the effective area curves for the extractions
of the source, PhotonFlux and EnergyFlux exhibit source-dependent
calibration errors.
Note (10): "Emed" (MedianEnergy) is the median energy of extracted events,
corrected for background but dependent on the shape of the effective
area curves for the extractions of the source (Broos+ 2010ApJ...714.1582B 2010ApJ...714.1582B,
Section 7.3).
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Catalog Declared counterpart catalog (1)
9- 15 A7 --- Label X-ray source candidate label
17- 21 I5 ct Nct [0/74445] Net counts detected (2)
23- 29 E7.2 ct/cm2/s XFlx [1.7e-09/0.00015] Photon flux;
photons/cm2/s (2)
31- 33 F3.1 keV Emed [0.7/4.7] Median energy (2)
35- 38 I4 --- ID [16/1038] Identifier in Catalog
40- 40 A1 --- f_ID Flag on ID (3)
42- 43 I2 h RAh [5] Hour of Right Ascension (J2000)
45- 46 I2 min RAm [37/39] Minute of Right Ascension
48- 53 F6.3 s RAs Second of Right Ascension
55- 55 A1 --- DE- [-] Sign of the Declination (J2000)
56- 57 I2 deg DEd [69/69] Degree of Declination (J2000)
59- 60 I2 arcmin DEm [0/11] Arcminute of Declination
62- 66 F5.2 arcsec DEs Arcsecond of Declination
68- 69 A2 --- rPos Position source (4)
71- 74 F4.2 arcsec Sep [0.01/1.1] Separation (5)
76- 94 I19 --- Gaia ? Gaia DR2 identifier
96-107 I12 --- VMC ? VISTA Magellanic Survey (VMC)
identifier (6)
109-128 A20 --- HTTP Source label in the Hubble Tarantula
Treasury Project (HTTP) catalog;
Sabbi+ 2016, J/ApJS/222/11 (7)
130-136 A7 --- Model Modeling information (8)
138-237 A100 --- Notes Additional notes
--------------------------------------------------------------------------------
Note (1): Catalogs as follows:
VFTS = the Very Large Telescope (VLT)-FLAMES Tarantula Survey catalog
(Evans+ 2011, J/A+A/530/A108; Walborn+ 2014, J/A+A/564/A40;
Evans+ 2015, J/A+A/574/A13); 74 occurrences
Doran13 = Doran+ 2013, J/A+A/558/A134 (32 occurrences)
Note (2): Reported properties of ACIS sources (Nct, XFlx, Emed from Table 2)
are derived by combining all observations. In some cases the source
detection is most significant in a single observation.
Nct suggests the quality of the extracted spectrum, but is unsuitable
for photometry. Apparent Photon Flux "XFlx" is a rough scaling of
Nct to account for source-to-source variations in exposure time,
effective area, and aperture size.
Note (3): Flag as follows:
e = We suspect that the identifiers VFTS416 and Doran390 refer
to the same star.
f = We suspect that the identifiers VFTS468 and Doran451 refer
to the same star.
Note (4): Coordinates from Gaia, Doran or VMC catalogs as follows:
G = Gaia coordinates (propagated to the mean epoch of the Chandra data,
Y2014.5) and uncertainties were adopted.
D+ = Doran+ 2013, J/A+A/558/A134 coordinates; corrected using frame shifts
derived using Gaia and uncertainties estimated by the authors.
V = VMC coordinates were adopted and uncertainties were estimated by
the authors.
Note (5): Separation between ACIS source and star's Adopted Coordinates;
median is 0.15 arcsec.
Note (6): The VMC survey catalog (see II/351 and II/375) reports NIR sources
across the entire T-ReX field to limiting magnitudes of Y=21.1,
J=21.3, and KS=20.7 with comparable spatial resolution to ACIS on-axis
data. We have used data from the third data release.
Note (7): HTTP source labels are based on the original published coordinates
and do not reflect our corrected position. The nomenclature is
<[SLA2016] JHHMMSS.sss+DDMMSS.ss> in Simbad.
Note (8): Modeling of the T-ReX spectrum is described by references as follows:
C22 = Crowther et al. 2022MNRAS.515.4130C 2022MNRAS.515.4130C
T19 = Tehrani K. 2019 Dissertation Univ. of Sheffield
P18 = Pollock et al. 2018MNRAS.474.3228P 2018MNRAS.474.3228P
C15 = Clark et al. 2015A&A...579A.131C 2015A&A...579A.131C
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Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Label X-ray source candidate label (1)
10- 12 F3.1 arcsec ePos [0/1.8]? X-ray positional uncertainty
14- 17 F4.2 arcsec SepGV [0/2.3]? Separation between ACIS source and
Gaia+VMC source
19- 37 I19 --- Gaia ? Gaia DR2 identifier
39- 50 I12 --- VMC ? VMC (Cioni+ 2011, see II/351) identifier
52- 53 I2 mag Kmag [10/21]? Apparent K band magnitude
55- 57 F3.1 arcsec SepHTTP [0/1.6]? Separation between ACIS source and
HTTP source
59- 78 A20 --- HTTP Source label in HTTP catalog
(Sabbi+ 2016, J/ApJS/222/11) (2)
80- 87 A8 mas Shift Shift applied to the published HTTP position
89- 90 I2 mag F555Wmag [17/26]? HST ACS/WFC F555W band apparent
magnitude
92- 94 F3.1 arcsec SepSAGE [0/1.5]? Separation between ACIS source and
SAGE source
96- 114 A19 --- SAGE The Spitzer Surveying the Agents of Galaxy
Evolution (SAGE) identifier
(Meixner+ 2006, J/AJ/132/2268)
116- 117 I2 mag 3.6mag [8/18]? SAGE 3.6 micron band apparent
magnitude
119- 169 A51 --- SName Simbad identifier
--------------------------------------------------------------------------------
Note (1): Using our judgement, we assert two associations that were not found
by automated methods:
Pulsar PSR J0537-6910 ≡ T-Rex 053747.40-691020.2 (p1_255);
the low-mass star HD 269921 ≡ T-ReX 053834.66-685306.1 (pass52_4).
Note (2): Among the X-ray-emitting objects likely to be detected by HTTP,
those of most interest to us are massive stars and T Tauri stars.
Thus, we made two photometry selections designed to select those
objects: a magnitude cut (F555<19) to select massive stars and a
color-magnitude selection in the F555W versus F555W-F775W diagram
approximating the locus of T Tauri stars in Figure 20 of
Ksoll+ 2018MNRAS.479.2389K 2018MNRAS.479.2389K. Those selections reduced the size of the
HTTP catalog from >8x105 to 29,445 rows. See Appendix A.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 20-Nov-2024