J/ApJ/505/50 JK photometry in SA 57-6575, Her 1-5677 fields (Bershady+, 1998)
Near-infrared galaxy counts to J and K∼24 as a function of image size.
Bershady M.A., Lowenthal J.D., Koo D.C.
<Astrophys. J. 505, 50 (1998)>
=1998ApJ...505...50B 1998ApJ...505...50B
ADC_Keywords: Galaxies, IR ; Photometry, infrared
Keywords: cosmology: observations - galaxies: evolution - galaxies: photometry -
galaxies: statistics - galaxies: structure - infrared: galaxies
Abstract:
We have used the Keck 10m telescope to count objects as a function of
image size in two high Galactic latitude fields covering 1.5arcmin2
and reaching 50% completeness depths of K=24 and J=24.5 for stellar
sources. Our counts extend ∼1mag deeper in K than those of surveys
with other telescopes; complement other Keck surveys in the K-band
that provide counts at comparable or shallower depths but that have
not utilized image structure; and extend by several magnitudes the
J-band counts from brighter surveys using smaller telescopes that
cover larger areas.
Objects:
----------------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------------
13 07 48.7 +29 17 44 SA 57-6575 = [K80] SA 57 6575
17 20 58.9 +49 46 55 Herc 1-5677 = [K80] Herc-1 5677
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2a.dat 69 130 Source catalog in SA 57-6575
table2b.dat 69 85 Source catalog in Herc 1-5677
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2a.dat, table2b.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Field Field name (SA 57-6575 or Herc 1-5677)
13- 17 A5 --- ID Identification label (1)
18 A1 --- n_ID [cdefg] Note on ID (2)
20- 24 F5.1 arcsec Dx Offset in the x dimension of the
NIRC detector (3)
26- 30 F5.1 arcsec Dy Offset in the y dimension of the
NIRC detector (3)
32- 36 F5.2 mag Jmag ? J total magnitude (4)
38- 41 F4.2 mag e_Jmag ? rms uncertainty on Jmag
43- 47 F5.2 mag Kmag ? K total magnitude (4)
49- 52 F4.2 mag e_Kmag ? rms uncertainty on Kmag
54 A1 --- l_Prad Limit flag on Prad
55- 58 F4.2 arcsec Prad Apparent radius θ0.5 for η=0.5 (5)
60- 63 F4.2 arcsec e_Prad ? rms uncertainty on Prad
65 A1 --- C [ls] Object class, identifying the size of
the source, (l) large and (s) small
67- 69 A3 --- Sam [J,K ] Sample, identifying on which image(s)
a source was detected, J and/or K
--------------------------------------------------------------------------------
Note (1): Designations are:
* skNNN or sjNNN for SA 57-6575 field
* hkNNN or hjNNN for Herc 1-5677 field
The objects are identified as <[BLK98] skNNN> and <[BLK98] hjNNN> in Simbad
Note (2): the notes have the following meaning:
c = sk144 is object SA 57-6575.
d = hk066 is object Herc 1-5677.
e = sk201 and hk124 are on the edge of their respective J-band images;
J-magnitudes are estimates based on simple aperture photometry.
f = sk045 and hk076 have size upper limits only.
g = hj106 and hj101 are sources split from brighter objects in the
J-band image with no corresponding sources split in the K-band
image. The neighboring brighter source for hj106 is hk099, and for
hj101 the brighter, neighboring source is hk091.
Note (3): Absolute coordinates (epoch 1950) can be generated from Dx, Dy
and the rotation of the NIRC detector and coordinates (see Fig.1)
RA[SA576575] = 13h05m25.80s + (0.0701Dx)s - (0.0309Dy)s;
DE[SA576575] = +29°33'44.3" + (0.404Dx)" + (0.915Dy)";
RA[Herc1-5677]= 17h19m43.1s + (0.0705Dx)s + (0.0756Dy)s;
DE[Herc1-5677]= +49°49'47" + (0.731Dx)" - (0.682Dy)".
Note (4): Magnitudes listed without estimated uncertainties are 1σ
upper limits. Sources missing one of their J- or K-magnitudes were
detected in one band but were not within the area of the image for the
other band. A few sources have magnitudes and uncertainties listed for
both bands, but are too faint, given their location in the images, to
be counted in one of the two bands.
Note (5): Petrosian radius: η is the ratio of the surface brightness at
radius θ to the average surface brightness interior to θ.
SA 57 radii for sources detected only in the J-band image are scaled
by a factor of 0.762 to the seeing conditions of the K-band image
based on simulations of model light profiles (see text)
--------------------------------------------------------------------------------
History: From ApJ electronic version
(End) James Marcout, Patricia Bauer [CDS] 19-Nov-1998