J/AJ/144/179 AKARI-LMC Point-source catalog (Kato+, 2012)
AKARI Infrared Camera survey of the Large Magellanic Cloud.
I. Point-source catalog.
Kato D., Ita Y., Onaka T., Tanabe T., Shimonishi T., Sakon I., Kaneda H.,
Kawamura A., Wada T., Usui F., Koo B.-C., Matsuura M., Takahashi H.
<Astron. J., 144, 179 (2012)>
=2012AJ....144..179K 2012AJ....144..179K
ADC_Keywords: Surveys ; Magellanic Clouds ; Photometry, infrared
Mission_Name: AKARI
Keywords: catalogs - infrared: galaxies - infrared: stars - Magellanic Clouds -
surveys
Abstract:
We present a near- to mid-infrared point-source catalog of five
photometric bands at 3.2, 7, 11, 15, and 24µm for a 10deg2 area
of the Large Magellanic Cloud (LMC) obtained with the Infrared Camera
on board the AKARI satellite. To cover the survey area the
observations were carried out at three separate seasons from 2006 May
to June, 2006 October to December, and 2007 March to July. The
10σ limiting magnitudes of the present survey are 17.9, 13.8,
12.4, 9.9, and 8.6mag at 3.2, 7, 11, 15, and 24µm, respectively.
The photometric accuracy is estimated to be about 0.1mag at 3.2µm
and 0.06-0.07 mag in the other bands. The position accuracy is 0.3" at
3.2, 7, and 11µm and 1.0" at 15 and 24µm. The sensitivities at
3.2, 7, and 24µm are roughly comparable to those of the Spitzer
SAGE LMC point-source catalog, while the AKARI catalog provides the
data at 11 and 15 µm, covering the mid-infrared spectral range
contiguously. Two types of catalog are provided: a Catalog and an
Archive. The Archive contains all the detected sources, while the
Catalog only includes the sources that have a counterpart in the
Spitzer SAGE point-source catalog. The Archive contains about 650,000,
140,000, 97,000, 43,000, and 52,000 sources at 3.2, 7, 11, 15, and
24µm, respectively. Based on the catalog, we discuss the luminosity
functions at each band, the color-color diagram, and the
color-magnitude diagram using the 3.2, 7, and 11µm band data.
Stars without circumstellar envelopes, dusty C-rich and O-rich stars,
young stellar objects, and background galaxies are located at distinct
regions in the diagrams, suggesting that the present catalog is useful
for the classification of objects toward the LMC.
Description:
The photometric catalog covers about 10 square degrees of the LMC with
wavelengths of N3 (3.2 micron), S7 (7.0 micron), S11 (11 micron), L15
(15.0 micron), and L24 (24.0 micron). The fluxes for zero magnitude
for the five IRC bands are 343.34, 74.956, 38.258, 16.034, and 8.0459
Jy, respectively (Tanabe et al. 2008 PASJ, 60, S375).
The catalog contains about a million sources. The 10 sigma limiting
magnitudes are estimated as 17.9, 13.8, 12.4, 9.9 and 8.6mag at N3,
S7, S11, L15, and L24, respectively, and the 90 percent completeness
limits are 14.6, 13.4, 12.6, 10.7, and 9.3 mag at N3, S7, S11, L15,
and L24, respectively.
The catalog consists of "Catalog" and "Archive". "Catalog" includes
sources that have counterparts in the version 3.1 of the SAGE-PSC with
a positional tolerance of 3 arcsec (Meixner et al. 2006 AJ, 132,
2268).
"Archive" includes all detected sources and thus has more and fainter
sources than "Catalog", which may contain potential false detection or
sources with larger photometric uncertainties.
In total, "Catalog" contains 660286 sources and "Archive" has 802285
sources. Each source in the all-band catalog has a name which consist
of the following parts:
"AKARI-LMCA(C) Jhhmmss.ss-ddmmss.s".
The second column of the catalog corresponds to the acronym of the
catalog, "AKARI-LMCC" for "Catalog" and "AKARI-LMCA" for "Archive",
and the third column the coordinates, "Jhhmmss.ss-ddmmss.s". Please
use these denotation in scientific articles.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
lmccat01.dat 554 660286 *Catalog part (more reliable sources)
lmcarc01.dat 554 802285 *Archive (all detected sources)
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Note on lmccat01.dat: includes sources that have counterparts in the
version 3.1 of the SAGE-PSC with a positional tolerance of 3arcsec
(Meixner et al., 2006; see Cat. II/305)
Note on lmcarc01.dat: may contain potential false detection or sources with
larger photometric uncertainties.
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See also:
II/305 : SAGE LMC and SMC IRAC Source Catalog (IPAC 2009)
J/AJ/145/32 : AKARI-LMC Near-infrared Spectroscopic Catalog (Shimonishi+, 2013)
http://www.ir.isas.jaxa.jp/AKARI/Archive/Catalogues/ : AKARI Catalogues
Byte-by-byte Description of file: lmccat01.dat lmcarc01.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- ObjID Internal Object ID (56xxxxxx for Catalog,
51xxxxxx for Archive)
10- 18 A9 --- --- (AKARI-LMC) an acronym of the catalog
19 A1 --- C [CA] "C" for Catalog, "A" for Archive
21- 39 A19 --- LMC Source identifier (JHHMMSS.ss-dDMMSS.s)
41- 50 F10.6 deg RAdeg Right ascension (J2000)
52- 61 F10.6 deg DEdeg Declination (J2000)
63 I1 --- b [0/4] "eqband" flag (band of position) (1)
65- 71 F7.3 pix N3x ?=999.999 N3 x pixel coordinate
73- 79 F7.3 pix N3y ?=999.999 N3 y pixel coordinate
81- 86 F6.3 mag N3mag ?=99.999 N3 (3.2um) magnitude
88- 93 F6.3 mag e_N3mag ?=99.999 N3 magnitude error (4)
95-100 F6.3 mag E_N3mag ?=99.999 N3 magnitude total error (4)
102-108 F7.3 --- N3chi ?=99.999 N3 PSF-fit χ parameter (5)
110-116 F7.3 --- N3sh ?=99.999 N3 sharpness (6)
118-136 A19 "datime" N3t ? N3 Observing date/time
138-146 F9.1 --- N3pid ?=9999999.9 N3 observing Pointing Identifier
148-154 I07 --- N3fl ?=9999999 N3 7-digit flag (2)
156-157 I2 --- N3m [0/2] Number of S7 sources matching N3 (3)
159-163 F5.2 arcsec N3r ?=99.99 Distance of nearest S7 match (3)
165-171 F7.3 pix S7x ?=999.999 S7 x pixel coordinate
173-179 F7.3 pix S7y ?=999.999 S7 y pixel coordinate
181-186 F6.3 mag S7mag ?=99.999 S7 (7.1um) magnitude
188-193 F6.3 mag e_S7mag ?=99.999 S7 magnitude error (4)
195-200 F6.3 mag E_S7mag ?=99.999 S7 magnitude total error (4)
202-208 F7.3 --- S7chi ?=99.999 S7 PSF-fit χ parameter (5)
210-216 F7.3 --- S7sh ?=99.999 S7 sharpness (6)
218-236 A19 "datime" S7t ? S7 Observing time
238-246 F9.1 --- S7pid ?=9999999.9 S7 observing Pointing identifier
248-254 I07 --- S7fl ?=9999999 S7 7-digit flag (2)
256-257 I2 --- S7m [0/3] Number of S11 sources matching S7
259-263 F5.2 arcsec S7r ?=99.99 distance of nearest S11 match (3)
265-271 F7.3 pix S11x ?=999.999 S11 x pixel coordinate
273-279 F7.3 pix S11y ?=999.999 S11 y pixel coordinate
281-286 F6.3 mag S11mag ?=99.999 S11 (10.5um) magnitude
288-293 F6.3 mag e_S11mag ?=99.999 S11 magnitude error (4)
295-300 F6.3 mag E_S11mag ?=99.999 S11 magnitude total error (4)
302-308 F7.3 --- S11chi ?=99.999 S11 PSF-fit χ parameter (5)
310-316 F7.3 --- S11sh ?=99.999 S11 sharpness (6)
318-336 A19 "datime" S11t ? S11 Observing time
338-346 F9.1 --- S11pid ?=9999999.9 S11 observing Pointing identifier
348-354 I07 --- S11fl ?=9999999 S11 7-digit flag (2)
356-357 I2 --- S11m [0/5] Number of L15 sources matching S11 (3)
359-363 F5.2 arcsec S11r ?=99.99 Distance of nearest L15 match (3)
365-371 F7.3 pix L15x ?=999.999 L15 x pixel coordinate
373-379 F7.3 pix L15y ?=999.999 L15 y pixel coordinate
381-386 F6.3 mag L15mag ?=99.999 L15 (15.6um) magnitude
388-393 F6.3 mag e_L15mag ?=99.999 L15 magnitude error (4)
395-400 F6.3 mag E_L15mag ?=99.999 L15 magnitude total error (4)
402-408 F7.3 --- L15chi ?=99.999 L15 PSF-fit χ parameter (5)
410-416 F7.3 --- L15sh ?=99.999 L15 sharpness (6)
418-436 A19 "datime" L15t ? L15 Observing time
438-446 F9.1 --- L15pid ?=9999999.9 L15 observing Pointing identifier
448-454 I07 --- L15fl ?=9999999 L15 7-digit flag (2)
456-457 I2 --- L15m [0/5] Number of L24 sources matching (3)
459-463 F5.2 arcsec L15r ?=99.99 Distance of nearest L24 match (3)
465-471 F7.3 pix L24x ?=999.999 L24 x pixel coordinate
473-479 F7.3 pix L24y ?=999.999 L24 y pixel coordinate
481-486 F6.3 mag L24mag ?=99.999 L24 (22.9um) magnitude
488-493 F6.3 mag e_L24mag ?=99.999 L24 magnitude error (4)
495-500 F6.3 mag E_L24mag ?=99.999 L24 magnitude total error (4)
502-508 F7.3 --- L24chi ?=99.999 L24 PSF-fit χ parameter (5)
510-516 F7.3 --- L24sh ?=99.999 L24 sharpness (6)
518-536 A19 "datime" L24t ? L24 Observing time
538-546 F9.1 --- L24pid ?=9999999.9 L24 observing Pointing identifier
548-554 I07 --- L24fl ?=9999999 L24 7-digit flag (2)
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Note (1): "eqband" flag that indicates the band at which the
coordinates are determined:
0 = at N3 (3.2µm); astrometry accurate to 0.607arcsec
1 = at S7 (7.1µm); astrometry accurate to 0.413arcsec
2 = at S11 (10.4µm); astrometry accurate to 0.405arcsec
3 = at L15 (15.6µm); astrometry accurate to 0.962arcsec
4 = at L24 (22.9µm); astrometry accurate to 1.031arcsec
Note (2): The flags consist of seven digits "epsbpam" for exposure,
photometry, saturation, mux bleed, column pulldown, artifact, and
multiple (left to right):
* exposure:
0 = "short" exposure: 14.03s for N3, 1.75s for other bands;
1 = "long" exposure: 133.24s for N3, 147.27s for other bands
* photometry: 0 = aperture photometry, 1 = PSF fitting photometry
* saturation: 1 = saturated sources or nearby sources
* column pulldown: 1 = sources with a possibility to be affected by
column pulldown belt (reduction in intensity of the columns in
which bright sources are detected).
* mux bleed: 1 = images suffering from the "mux bleed" (signals leaking
from bright point sources, making false faint point-like sources every
4 pixels along a row, in which the bright sources are detected)
* artifact: 1 = sources affected by artifacts of bright sources due to
the internal reflections in the beam splitter
* multiple detection: number of nearby sources
Note (3): The number of the matched sources (MAT) and the distance from the
nearest matched source (DR) are given for the longer band:
* merging the N3 list with the S7 list,
* merging the N3-S7 list with the S11 list,
* merging the N3-S7-S11 list with the L15 list,
* merging the N3-S7-S11-L15 list with the L24 list.
Note (4): the photometric errors are labelled
e_xxx = uncertainty from ALLSTAR
E_xxx = total error, including errors in the aperture correction,
read-out noise and conversion factor
Note (5): the parameter χ increases with the difference in shape
between the source and the PSF profile; no value is given when the
aperture photometry is used.
Note (6): a positive sharpness indicates that the source is more extended
than the PSF profile, suggesting that the source may be extended
(galaxy, unresolved multi-star); a negative sharpness indicates a
source less extended than the PSF (cosmic ray or image defect); no
value is given when the aperture photometry is used.
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Acknowledgements:
Copied at http://www.ir.isas.jaxa.jp/AKARI/Archive/Catalogues/LMCPSC_V1/
History:
* 12-Oct-2012: The catalog format has been changed from the previous beta
version. Photometric errors without systematic errors have been added
and the name of the pointing ID has been added.
(End) Daisuke Kato [ISAS/JAXA], Takashi Onaka [Univ of Tokyo] 16-Oct-2012