J/AJ/123/2070 ISO deep asteroid search (Tedesco+, 2002)
The Infrared Space Observatory deep asteroid search.
Tedesco E.F., Desert F.-X.
<Astron. J. 123, 2070 (2002)>
=2002AJ....123.2070T 2002AJ....123.2070T
ADC_Keywords: Minor planets ; Solar system ; Spectra, infrared
Mission_Name: ISO
Keywords: infrared radiation - minor planets, asteroids - solar system: general
Abstract:
A total of six deep exposures (using the astronomical observation
template CAM01 with a 6" pixel field of view) through the ISOCAM LW10
filter (IRAS band 1, i.e., 12µm) were obtained on a ∼15' square
field centered on the ecliptic plane. Point sources were extracted
using the technique described in 1999 by Deert et al. Twoknown
asteroids appear in these frames, and 20 sources moving with
velocities appropriate for main-belt asteroids are present. Most of
the asteroids detected have flux densities less than 1 mJy, that is,
between 150 and 350 times fainter than any of the asteroids observed
by IRAS. These data provide the first direct measurement of the
12µm sky-plane density for asteroids on the ecliptic equator. The
median zodiacal foreground, as measured by ISOCAM during this survey,
is found to be 22.1±1.5mJy/pixel, i.e. 26.2±1.7MJy/sr. The results
presented here imply that the actual number of kilometer-sized
asteroids may be higher than several recent estimates based upon
observations at visual wavelengths and are in reasonable agreement
with the statistical asteroid model. Using results from the
observations presented here, together with three other recent
population estimates, we conclude that the cumulative number of
main-belt asteroids with diameters greater than 1km is
(1.2±0.5)x106.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 100 527 All Point Sources Extracted from the Six IDAS Maps
table3.dat 93 63 IDAS field inertial point sources
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See also:
B/astorb : Orbits of Minor Planets (Bowell 1998)
VII/91 : IRAS Asteroid and Comet Survey (Veeder+ 1986)
J/A+A/338/340 : Asteroids as IR Standards for ISOPHOT (Mueller+ 1998)
J/A+A/375/275 : Asteroidal I, J, K in the DENIS Survey (Baudrand+ 2001)
J/AJ/112/2319 : Asteroid masses (Hilton+ 1996)
Table 1: Map field centers
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Map RA (J2000.0) DE Raster Longitude (Ecliptic) latitude
(J2000.0 Equinox)
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1 22 08 38.6 -08 34 10.4 17 x 17 338.000000 0.002471
2 22 08 42.5 -08 33 52.1 17 x 17 338.016800 0.001180
3 22 08 38.6 -08 34 10.4 15 x 15 338.000000 0.002471
4 22 08 41.6 -08 33 56.4 15 x 15 338.012900 0.001483
5 22 08 38.6 -08 34 10.4 17 x 17 338.000000 0.002471
6 22 08 42.5 -08 33 52.1 17 x 17 338.016800 0.001180
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- [TD2002] Identification number, [TD2002] 2-NNNN (G1)
5- 15 F11.6 deg RAdeg Decimal degree Right Ascension (J2000) (G2)
16- 25 F10.6 deg DEdeg Decimal degree Declination (J2000) (G2)
26- 31 I6 mJy FD Flux density in LW10 band (∼IRAS 12µm)
32- 35 I4 mJy e_FD The 1 σ uncertainty in FD
36- 40 F5.1 --- SNR Signal-to-noise ratio
41- 42 I2 --- Q1 Quality 1 code (3)
43- 44 I2 --- Q2 Quality 2 code (4)
45- 46 I2 --- Q3 Quality 3 code of source detection (5)
47- 60 F14.5 d JD Julian Date of midpoint of observation
62 I1 --- G [0,1] Brigher source code (6)
64 I1 --- C [0,1] Multiply-sample region code (7)
65- 69 F5.1 mag Rmag Red magnitude from the USNO-A2 catalog (G3)
70- 83 A14 --- USNO Name from the from the USNO-A2 catalog (G3)
84- 85 I2 --- Ass Number of USNO-A2 sources associated with
the ISO source (G3)
86- 89 I4 --- UNum Number from the USNO-A2 catalog (G3)
90- 94 F5.1 arcsec Dist Distance from USNO-A2 catalog source (9)
95- 97 I3 arcsec DistRA Distance in RA from USNO-A2 catalog source (10)
98-100 I3 arcsec DistDE Distance in DE from USNO-A2 catalog source (10)
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Note (3): From 0 (worst) to 4 (best).
A measure of the source reliability based upon the number of times a
sky pixel was seen by different pixels on the camera. It uses the 3
flux values with the lowest noise out of the 3 subraster fluxes in
which the source was detected.
See Desert et al., 1999A&A...342..363D 1999A&A...342..363D, Sec 3.4 for details.
Note (4): From 0 (worst) to 4 (best).
As for Q1 but keeping only the two flux values with the lowest noise
out of the 3 subraster fluxes.
See Desert et al., 1999A&A...342..363D 1999A&A...342..363D, Sec 3.4 for details.
Note (5): From 0 (worst) to 4 (best).
A quality based upon the final map compared with the two best submaps
out of the three that produce the final one.
Q3 = 4 for sources with SNR>5 and with the best 2 SNRs above 3;
Q3 = 3, as for 4 but with the best 2 SNRs above 2;
Q3 = 2, as for 4 but with the best 2 SNRs not above 2;
Q3 = 1, other point sources.
Note (6): Brigher source code:
0 = if close to a brighter source (and so possibly spurious);
1 = otherwise.
Note (7): 1 if in multiply-sampled region of map.
Note (9): As reduced by CDS-VizieR, http://cdsweb.u-strasbg.fr/CDS.html
-1.0 if there is no USNO catalog association.
Note (10): As reduced by CDS-VizieR, http://cdsweb.u-strasbg.fr/CDS.html
Rounded to nearest arcsecond.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- [TD2002] Identification number, [TD2002] 3-NN (G1)
4- 13 F10.6 deg RAdeg Right ascension, in decimal degrees
(J2000.0) (G2)
15- 24 F10.6 deg DEdeg Declination, in decimal degrees (J2000.0) (G2)
27- 31 I5 mJy FD Flux density in LW10 band (∼IRAS 12µm)
33- 35 I3 mJy e_FD The 1 σ uncertainty in FD
37- 40 F4.1 ---- SNR Signal-to-noise ratio
42- 45 F4.1 mag Rmag ? Red magnitude from the USNO-A2 catalog (G3)
47- 59 A13 --- USNO Name from the from the USNO-A2 catalog (G3)
61-100 A40 --- Ass Number of USNO-A2 sources associated with
the ISO source, separated by comma (G3)
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Global notes:
Note (G1): Coded as
0 - 999 from Map 1, 1000 - 1999 from Map 2,
4000 - 4999 from Map 3, 5000 - 5999 from Map 4,
8000 - 8999 from Map 5, and 9000 - 9999 from Map 6.
Note (G2): For inertial sources the positions are apparent geocentric as
they are tied to the USNO-SA2 catalog. For solar system objects the
positions are ISO-centric.
Note (G3): As reduced by CDS-VizieR,
http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=USNO-A2.0
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 04-Jun-2002