J/MNRAS/503/5351 Galactic extinction at low Galactic latitudes (Schroder+, 2021)
A comparative analysis of Galactic extinction at low Galactic latitudes.
Schroder A.C., Van Driel W., Kraan-Korteweg R.C.
<Mon. Not. R. Astron. Soc., 503, 5351-5366 (2021)>
=2021MNRAS.503.5351S 2021MNRAS.503.5351S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, IR ; Galaxies, photometry ; Extinction
Keywords: dust, extinction - galaxies: photometry - infrared: galaxies
Abstract:
We use near-infrared (J-K) colours of bright 2MASS galaxies,
measured within a 7-arcsec-radius aperture, to calibrate the
Schlegel, Finkbeiner & Davis DIRBE/IRAS Galactic extinction map at low
Galactic latitudes (|b|<10°). Using 3460 galaxies covering a
large range in extinction (up to AK=1.15mag or E(B-V)~=3.19mag), we
derive a correction factor f=0.83±0.01 by fitting a linear
regression to the colour-extinction relation, confirming that the
Schlegel et al. maps overestimate the extinction. We argue that the
use of only a small range in extinction (e.g., AK<0.4mag)
increases the uncertainty in the correction factor and may
overestimate it. Our data confirm the Fitzpatrick extinction law for
the J- and K-band. We also tested four all-sky extinction maps based
on Planck satellite data. All maps require a correction factor as
well. In three cases, the application of the respective extinction
correction to the galaxy colours results in a reduced scatter in the
colour-extinction relation, indicating a more reliable extinction
correction. Finally, the large galaxy sample allows an analysis of the
calibration of the extinction maps as a function of Galactic longitude
and latitude. For all but one extinction map, we find a marked offset
between the Galactic Centre and Anticentre region, but not with the
dipole of the cosmic microwave background. Based on our analysis, we
recommend the use of the GNILC extinction map by Planck Collaboration
XLVIII with a correction factor f=0.86±0.01.
Description:
Catalogues of the adopted velocity measurements and k-corrections.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tables3a.dat 159 6913 2MZOA catalogue with k-correction
tables3b.dat 158 502 2MEBV catalogue with k-correction
tables4a.dat 159 276 2MZOA supplementary catalogue with k-correction
tables4b.dat 81 14 2MEBV supplementary catalogue with k-correction
tables5a.dat 55 199 List of references for published velocity
measurements
tables5b.dat 47 13 List of references for as yet unpublished
velocity measurements
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See also:
J/MNRAS/482/5167 : The 2M-ZoA galaxy catalogue (Schroder+, 2019)
Byte-by-byte Description of file: tables3?.dat tables4?.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- 2MASX The 2MASX J identifier
(HHMMSSss-DDMMSSs J2000 format)
19- 25 F7.3 deg GLON Galactic longitude
28- 34 F7.3 deg GLAT Galactic latitude
36- 42 F7.3 mag E(B-V) The (B-V) color excess (1)
45- 49 F5.2 mag (J-K)0 ? Extinction-corrected 2MASX isophotal
colour J-K (2)
52 A1 --- gal [gp-] Sample flag galaxy (3)
55 A1 --- off [oe-] Object offset flag (4)
58- 59 A2 --- vel [ogh*- :?] Velocity flag for the final
adopted velocity (5)
62 A1 --- 2MRS [*-] 2MRS flag (6)
65- 69 I5 km/s v(adpt) ? Adopted velocity according to the flag
in Column vel
70 A1 --- n_v(adpt) [*] a star replaces the values in case of
unpublished values
72- 74 I3 km/s e_v(adpt) ? Error of adopted velocity
75 A1 --- nev(adpt) [*] a star replaces the values in case of
unpublished values
77- 81 F5.2 mag k-corr ? k-correction for the colour (J-K)
84- 89 I6 km/s v(op) ? Adopted optical velocity for this object
90 A1 --- n_v(op) Note on v(op) (] or *) (7)
93- 96 I4 km/s e_v(op) ? Optical velocity error for this object
97 A1 --- nev(op) Note on e_v(op) (] or *) (7)
101-119 A19 --- r_v(op) Reference (bibliographic code) of the
optical velocity for this object,
in tables5a and tables5b
120 A1 --- nrv(op) Square bracket indicate a discarded
measurement (8)
124-128 I5 km/s v(hi) ? Adopted HI velocity for this object
129 A1 --- n_v(hi) Note on v(hi) (7)
133-135 I3 km/s e_v(hi) ? HI velocity error for this object
136-137 A2 --- nev(hi) Note on e_v(hi) (7)
140-158 A19 --- r_v(hi) Reference (bibliographic code) of the HI
velocity for this object,
in tables5a and tables5b
159 A1 -- nrv(hi) Square bracket indicate a discarded
measurement (8)
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Note (1): As derived from the IRAS/DIRBE maps (Schlegel et al.,
1998ApJ...500..525S 1998ApJ...500..525S).
Note (2): An additional diameter-dependent extinction correction has been
applied (Riad et al., 2010MNRAS.401..924R 2010MNRAS.401..924R); only given for objects
flagged as galaxies (gal)
Note (3): Sample flag galaxy as follows:
g = galaxy (object classes 1-4)
p = galaxy candidates (class 5)
Note (4): Object offset flag as follows:
o = coordinates that are offset from the centre of the object
e = detections near the edge of an image (at an offset position from the
object centre) which were detected with properly centred coordinates
on the adjacent image
Note (5): Velocity flag for the final adopted velocity as follows:
o = an optical measurement and
o? = a questionable optical measurement or object ID
g = the velocity shows it to be a Galactic object
h = for published H I velocity
h: = uncertain H I velocity
h? = is an uncertain object ID (based on a radio telescope's large beam size
that may include nearby galaxies)
* = indicates a yet unpublished measurement
Note (6): 2MRS flag as follows: a star denotes if our adopted velocity, error
or reference deviates from the values given in the 2MRS catalogue
(Huchra et al., 2012ApJS..199...26H 2012ApJS..199...26H, Cat. J/ApJS/199/26,
Macri et al., 2019ApJS..245....6M 2019ApJS..245....6M, Cat. J/ApJS/245/6).
Note (7): Note as follows:
square bracket indicate a discarded measurement
a star replaces the values in case of unpublished measurements
Note (8): The bibliographic code is resolved in Table S5.
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Byte-by-byte Description of file: tables5a.dat tables5b.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- Bibcode Bibcode of reference, as given in
Tables S3 and S4 (1)
22- 56 A35 --- Ref Author(s) and year of publication
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Note (1): Exceptions to the Bibcode are
Simbad = for a velocity as listed by Simbad but with no reference quoted
HIZOA-GB = stands for the Parkes Multibeam HIZOA survey of the Galactic bulge
NRT = stands for the Nancay Radio Telescope observing campaign of the
2MZOA galaxy sample
PKS = stands for the Parkes Radio Telescope observing campaign of the
2MZOA galaxy sample;
for the optical observing campaign, entries are given as year,
2MRS or 2MZO code, telescope ID, four zeros and the initial of the observer
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Acknowledgements:
Anja Schroeder, anja(at)hartrao.ac.za
References:
Schroder et al., 2019MNRAS.482.5167S 2019MNRAS.482.5167S, Cat. J/MNRAS/482/5167
(End) Patricia Vannier [CDS] 06-Oct-2021