J/MNRAS/516/824 Study of background galaxies of LMC (Bell+, 2022)
The intrinsic reddening of the Magellanic Clouds as traced by background
galaxies. III. The Large Magellanic Cloud.
Bell C.P.M., Cioni M.-R.L., Wright A.H., Nidever D.L., Chiang I.-D.,
Choudhury S., Groenewegen M.A.T., Pennock C.M., Choi Y., De Grijs R.,
Ivanov V.D., Massana P., Nanni A., Noel N.E.D., Olsen K., Van Loon J.T.,
Vivas A.K., Zaritsky D.
<Mon. Not. R. Astron. Soc. 516, 824-840 (2022)>
=2022MNRAS.516..824B 2022MNRAS.516..824B (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Galaxies ; Active gal. nuclei ; Photometry ;
Optical ; Infrared ; Redshifts ; Extinction ; Positional data
Keywords: surveys; dust, extinction - galaxies: ISM - Magellanic Clouds -
galaxies: photometry
Abstract:
We present a map of the total intrinsic reddening across ~= 90 deg2
of the Large Magellanic Cloud (LMC) derived using optical (ugriz) and
near-infrared (IR; YJKs) spectral energy distributions (SEDs) of
background galaxies. The reddening map is created from a sample of
222752 early-type galaxies based on the LEPHAREΧ2^_ minimization
SED-fitting routine. We find excellent agreement between the regions
of enhanced intrinsic reddening across the central (4 * 4 deg2)
region of the LMC and the morphology of the low-level pervasive dust
emission as traced by far-IR emission. In addition, we are able to
distinguish smaller, isolated enhancements that are coincident with
known star-forming regions and the clustering of young stars observed
in morphology maps. The level of reddening associated with the
molecular ridge south of 30 Doradus is, however, smaller than in the
literature reddening maps. The reduced number of galaxies detected in
this region, due to high extinction and crowding, may bias our results
towards lower reddening values. Our map is consistent with maps
derived from red clump stars and from the analysis of the star
formation history across the LMC. This study represents one of the
first large-scale categorizations of extragalactic sources behind the
LMC and as such we provide the lephare outputs for our full sample of
∼ 2.5 million sources.
Description:
In this study, in order to compute fluxes of the LMC background
galaxies, we use optical ugriz and near-IR YJKs photometry taken as
part of the SMASH and VMC surveys, respectively, that cover the
wavelength range 0.3-2.5µm. To do it, fluxes for each of our
targets are measured using LAMBDAR algorithm.
Secondly, as explained in Papers I and II, we use the fitting SEDs and
photometric redshift algorithm called LePHARE (i.e section 2 for more
details) to compute 2474235 redshift sources. Results are provided in
table1.dat. Similarly, we process computations for AGN sample of 21828
sources, results are available in table2.dat. Next, as explicited in
section 2.4.2, we compared spectroscopic and photometric redshift of
189 AGN behind the LMC, zspec are taken from literature references as
the table3.dat shows.
In addition to the extinction map done with 1504987 objects classified
as galaxies by LEPHARE in the full LMC sample (i.e see figure 8 top
panel of the section), we only take 222752 objects classified as ETGs
to make extinction map centered on LMC divided on 3348 square bins of
a total 96°2 area. The table4.dat gives bin positions, E(B-V)
median values and numbers of ETGs peer bin.
Objects:
----------------------------------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------------------------------
05 23 34.59 -69 45 21.9 NAME LMC = 1FGL J0538.9-6914
----------------------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 140 2474235 A LEPHARE output for the sources in the
full LMC sample
table2.dat 134 21828 A LEPHARE output for our AGN sample
table3.dat 57 189 Spectroscopically determined and photometric
redshifts for AGN sample behind the LMC
table4.dat 33 3348 Reddening values derived from ETGs within 3348
bins across the LMC
--------------------------------------------------------------------------------
See also:
J/MNRAS/504/1 : VMC RR Lyrae in LMC (Cusano+, 2021)
J/MNRAS/506/3540 : ASKAP-EMU ESP LMC Radio Continuum Survey (Pennock+, 2021)
J/MNRAS/499/993 : Small Magellanic Cloud's background galaxies (Bell+, 2020)
J/MNRAS/504/2983 : Reddening of SMC red clump stars (Tatton+, 2021)
J/MNRAS/508/245 : VMC survey XLIII. LMC star formation history (Mazzi+, 2021)
J/MNRAS/472/808 : YJKs light curves of SMC Classical Cepheids (Ripepi+, 2017)
J/MNRAS/504/1 : VMC RR Lyrae in LMC (Cusano+, 2021)
J/MNRAS/473/3131 : VMC survey. XXVI. SMC RR Lyrae stars (Muraveva+, 2018)
J/A+A/628/A51 : Magellanic Clouds reddening map (Joshi+, 2019)
J/A+A/616/A187 : SMC clusters age-dating & classification (Nayak+, 2018)
J/A+A/625/A14 : Reclassification of Cepheids in the Gaia DR2 (Ripepi+, 2019)
J/A+A/619/A8 : Cepheid period-luminosity-metallicity relation
(Groenewegen, 2018)
J/A+A/620/A99 : SMC Cepheids K-band and RV curves (Gieren+, 2018)
J/ApJ/699/539 : Cepheids in SN-Ia host galaxies (Riess+, 2009)
J/ApJ/876/85 : HST observations for LMC Cepheids (Riess+, 2019)
J/ApJ/832/176 : Classical Cepheids in MCs. I. LMC disk (Inno+, 2016)
J/ApJ/775/92 : MQS III: AGNs behind LMC and SMC (Kozlowski+, 2013)
J/ApJS/252/23 : E(V-I) reddening map of MCs from OGLE-IV RC stars
(Skowron+, 2021)
J/ApJS/194/22 : Magellanic Quasars Survey: QSOs behind SMC (Kozlowski+,2011)
J/ApJ/892/105 : Fourth catalog of Fermi LAT-detected AGNs (4LAC)
(Ajello+, 2020)
J/ApJ/746/27 : Magellanic Quasars Survey. II. AGNs behind LMC
(Kozlowski+, 2012)
J/AJ/154/199 : SMASH: Survey of the MAgellanic Stellar History
(Nidever+, 2017)
J/AJ/123/855 : Magellanic Clouds Photometric Survey: the SMC
(Zaritsky+, 2002)
J/AJ/114/2353 : AGNs and QSOs behind nearby galaxies (Crampton+, 1997)
J/A+A/549/A29 : Quasars behind the Magellanic system (Cioni+, 2013)
J/A+A/545/A128 : SMC XMM-Newton images (Haberl+, 2012)
VII/237 : HYPERLEDA. I. Catalog of galaxies (Paturel+, 2003)
VII/294 : The Million Quasars (Milliquas) catalogue, version 8
(Flesch, 2023)
VII/259 : 6dF galaxy survey final redshift release (Jones+, 2009)
II/375 : VISTA Magellanic Survey (VMC) catalog (YJKs) DR6
(Cioni+, 2011)
II/382 : VIKING catalogue data release 4 (Cross+, 2012)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 I7 --- ID Raw identifier number (ID)
9- 16 F8.5 deg RAdeg Right ascension (J2000) (RA)
18- 26 F9.5 deg DEdeg Declination (J2000) (Dec)
28- 35 F8.6 --- zBEST Best-fitting photometric redshift (zBEST)
37- 46 F10.6 --- b_zBEST [] Lower bound zBEST - 1σ standard
deviation corresponding to 16th percentile of
the posterior (zBEST,low)
48- 57 F10.6 --- B_zBEST [] Upper bound zBEST + 1σ standard
deviation corresponding to 84th percentile of
the posterior (zBEST,high)
59- 66 F8.4 --- zML ?=-99 The maximum likelihood photometric
redshift (zML)
68- 75 F8.4 --- b_zML []?=-99 Lower bound zML - 1σ standard
deviation corresponding to 16th percentile of
the posterior (zML,low)
77- 84 F8.4 --- B_zML []?=-99 High bound zML + 1σ standard
deviation corresponding to 84thth percentile
of the posterior (z_ML,high)
86- 87 I2 --- TempG The best-fitting galaxy SEDs template
correponds to AVEROI_NEW templates in Paper I
Bell et al. 2019MNRAS.489.3200B 2019MNRAS.489.3200B (Template_G/Q)
(1)
89- 99 E11.5 --- Chi2G Associated Χ2 value for the best-fitting
galaxy template (Chi2_G/Q)
101-108 F8.6 mag E(B-V) Best-fitting reddening E(B-V) value (EB-V)
110-118 F9.6 mag DM Best-fitting distance modulus (Dist_mod)
120 I1 --- Nbands Number of photometric bands in the SED
(No._bands)
122-124 I3 --- Context Combination of photometric bands in the SED
(Context) (2)
126-128 I3 --- TempS Best-fitting stellar template (Template_S)
130-140 E11.5 --- Chi2S Associated Χ2 value for the best-fitting
stellar template (Chi2_S)
--------------------------------------------------------------------------------
Note (1): Best-fitting galaxy templates are (1-21) E, (22-37) Sbc, (38-48) Scd,
(49-58) Irr, (59-62) Starburst.
Note (2): Context is a numerical representation in lephare specifying the
combination of bands present in the input catalogue and is defined as
the sum of 2i-1 from 1 to N, where i is the band number (in our
case, u = 1, g = 2,..., J = 7, and Ks = 8), and N is the total number
of bands.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- ID Raw identifier number (ID)
7- 14 F8.5 deg RAdeg Right ascension (J2000) (RA)
16- 24 F9.5 deg DEdeg Declination (J2000) (Dec)
26- 33 F8.6 --- zBEST Best-fitting photometric redshift (zBEST)
35- 42 F8.6 --- b_zBEST [] Lower bound zBEST - 1σ standard
deviation corresponding to 16th percentile of
the posterior (zBEST,low)
44- 51 F8.6 --- B_zBEST [] Upper bound zBEST + 1σ standard
deviation corresponding to 84th percentile of
the posterior (zBEST,high)
53- 60 F8.4 --- zML ?=-99 The maximum likelihood photometric
redshift (zML)
62- 69 F8.4 --- b_zML []?=-99 Lower bound zML - 1σ standard
deviation corresponding to 16th percentile of
the posterior (zML,low)
71- 78 F8.4 --- B_zML []?=-99 High bound zML + 1σ standard
deviation corresponding to 84thth percentile
of the posterior (z_ML,high)
80- 81 I2 --- TempQ The best-fitting quasars SEDs template
correponds to AVEROI_NEW templates in Paper I
Bell et al. 2019MNRAS.489.3200B 2019MNRAS.489.3200B (TemplateQ)
(1)
83- 93 E11.5 --- Chi2Q Associated Χ2 value for the best-fitting
quasars template (Chi2Q)
95-102 F8.6 mag E(B-V) Best-fitting reddening E(B-V) value (EB-V)
104-112 F9.6 mag DM Best-fitting distance modulus (Dist_mod)
114 I1 --- Nbands Number of photometric bands in the SED
(No._bands)
116-118 I3 --- Context Combination of photometric bands in the SED
(Context) (Context) (2)
120-122 I3 --- TempS Best-fitting stellar template (Template_S)
124-134 E11.5 --- Chi2S Associated Χ2 value for the best-fitting
stellar template (Chi2S)
--------------------------------------------------------------------------------
Note (1): Best-fitting AGN templates are (1) Seyfert 1.8, (2) Seyfert 2,
(3-5) type-1 QSO, (6-7) type-2 QSO, (8-9) Starburst/ULIRG,
(10) Starburst/Seyfert 2.
Note (2): Context is a numerical representation in lephare specifying the
combination of bands present in the input catalogue and is defined as
the sum of 2i-1 from 1 to N, where i is the band number (in our
case, u = 1, g = 2,..., J = 7, and Ks = 8), and N is the total number
of bands.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name AGN name designation (Name)
26- 28 A3 --- f_Name Flag on AGN zBEST and Chi2S values (f_Name) (1)
30- 34 F5.3 --- zsp Spectroscopic redshift (zspec)
36- 40 F5.3 --- zph Photometric redshift (zphot)
42- 47 F6.3 --- e_zph [] Lower uncertainty of zph (e_zph)
49- 54 F6.3 --- E_zph [] Upper uncertainty of zph (E_zph)
56- 57 I2 --- r_zsp Literature reference for zsp values (Ref) (2)
--------------------------------------------------------------------------------
Note (1): Flag as follows:
a = Associated 1σ limits on zBEST are unphysical as
e_zBEST > zBEST and/or E_zBEST < zBEST as explained in footnote 4
of Paper II Cameron et al. 2020MNRAS.499..993B 2020MNRAS.499..993B,
Cat. J/MNRAS/499/993, 17 cases in our sample
b = Associated Χ2 value for best-fitting stellar template is
lower than Χ2 value for best-fitting AGN template, 4 cases
in our sample
Note (2): Literature reference as follows:
1 = Ajello et al. 2020ApJ...892..105A 2020ApJ...892..105A, Cat. J/ApJ/892/105,
1 AGN in our sample
2 = Jones et al. 2009MNRAS.399..683J 2009MNRAS.399..683J, Cat. VII/259,
1 AGN in our sample
3 = Kozlowski et al. 2013ApJ...775...92K 2013ApJ...775...92K, Cat. J/ApJ/775/92,
127 AGNs in our sample
4 = Cowley et al. 1984ApJ...286..196C 1984ApJ...286..196C, 2 AGNs in our sample
5 = Dobrzycki et al. 2005A&A...442..495D 2005A&A...442..495D, 2 AGNs in our sample
6 = Crampton et al. 1997AJ....114.2353C 1997AJ....114.2353C, Cat. J/AJ/114/2353,
3 AGNs in our sample
7 = Cristiani & Tarenghi 1984A&A...132..351C 1984A&A...132..351C, 1 AGN in our sample
8 = Kozlowski et al. 2012ApJ...746...27K 2012ApJ...746...27K, Cat. J/ApJ/746/27,
46 AGNs in our sample
9 = Wang et al. 1991ApJ...374..475W 1991ApJ...374..475W, 1 AGN in our sample
10 = Dobrzycki et al. 2002ApJ...569L..15D 2002ApJ...569L..15D, 1 AGN in our sample
11 = Tinney 1999MNRAS.303..565T 1999MNRAS.303..565T, 1 AGN in our sample
12 = Geha et al. 2003AJ....125....1G 2003AJ....125....1G, 1 AGN in our sample
13 = Ivanov et al. 2016A&A...588A..93I 2016A&A...588A..93I, 1 AGN in our sample
14 = Kostrzewa-Rutkowska et al. 2018MNRAS.476..663K 2018MNRAS.476..663K,
1 AGN in our sample
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.5 --- DeltaRAdeg Right ascension bin offset (J2000)
(ΔRA) (1)
10- 17 F8.5 --- DeltaDEdeg Declination bin offset (J2000) (ΔDec)
(1)
19- 23 F5.3 --- E(B-V) Median interstellar dust extinction
(EB-V,med)
25- 29 F5.3 --- e_E(B-V) Median uncertainty standard deviation of E
(B-V) (σEB-V,med)
31- 33 I3 --- ETGs Number of early-type galaxies ETGs in the
bin across LMC footprint (NoETGs)
--------------------------------------------------------------------------------
Note (1): The origin of SMASH-VMC footprint is the center of LMC less an image
shift as (80.8935°,-69.7561°) - (0.5°,1°) equal to
(80.4935°,-70.7561°) = (RAdeg0,DEdeg0). Thus to retreive bin
sky position, it just needs to add bin offset as
(RAdeg0+ΔRA,DEdeg0+ΔDec).
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Bell et al., Paper I 2019MNRAS.489.3200B 2019MNRAS.489.3200B
Bell et al., Paper II 2020MNRAS.499..993B 2020MNRAS.499..993B, Cat. J/MNRAS/499/993
(End) Luc Trabelsi [CDS] 17-Jul-2025