J/ApJ/791/121 NIR albedos of main-belt asteroids (Masiero+, 2014)
Main-belt asteroids with WISE/NEOWISE: near-infrared albedos.
Masiero J.R., Grav T., Mainzer A.K., Nugent C.R., Bauer J.M., Stevenson R.,
Sonnett S.
<Astrophys. J., 791, 121 (2014)>
=2014ApJ...791..121M 2014ApJ...791..121M (SIMBAD/NED BibCode)
ADC_Keywords: Minor planets
Keywords: minor planets, asteroids: general
Abstract:
We present revised near-infrared albedo fits of 2835 main-belt
asteroids observed by WISE/NEOWISE over the course of its fully
cryogenic survey in 2010. These fits are derived from reflected-light
near-infrared images taken simultaneously with thermal emission
measurements, allowing for more accurate measurements of the
near-infrared albedos than is possible for visible albedo
measurements. Because our sample requires reflected light
measurements, it undersamples small, low-albedo asteroids, as well as
those with blue spectral slopes across the wavelengths investigated.
We find that the main belt separates into three distinct groups of 6%,
16%, and 40% reflectance at 3.4 µm. Conversely, the 4.6 µm
albedo distribution spans the full range of possible values with no
clear grouping. Asteroid families show a narrow distribution of 3.4
µm albedos within each family that map to one of the three observed
groupings, with the (221) Eos family being the sole family associated
with the 16% reflectance 3.4 µm albedo group. We show that
near-infrared albedos derived from simultaneous thermal emission and
reflected light measurements are important indicators of asteroid
taxonomy and can identify interesting targets for spectroscopic
follow-up.
Description:
To fit for NIR albedos of main-belt asteroids, we use data from the
WISE/NEOWISE all-sky single exposure source table, which are available
for download from the Infrared Science Archive (IRSA,
http://irsa.ipac.caltech.edu ; Cutri et al. 2012, xplanatory
Supplement to the WISE All-Sky Data Release Products,
http://wise2.ipac.caltech.edu/docs/release/allsky/expsup/index.html).
We extract photometric measurements of all asteroids observed by WISE
following the technique described in Masiero et al. (2011, J/ApJ/741/68)
and Mainzer et al. (2011ApJ...731...53M 2011ApJ...731...53M). In particular, we use
the NEOWISE observations reported to the MPC and included in
the MPC's minor planet observation database as the final validated
list of reliable NEOWISE detections of solar system objects.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 74 3080 Revised thermal fits of Main Belt asteroids
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See also:
J/ApJ/741/68 : Main Belt asteroids with WISE/NEOWISE. I. (Masiero+, 2011)
J/ApJ/770/7 : WISE/NEOWISE Main Belt asteroids: family members
(Masiero+, 2013)
J/A+A/578/A42 : Main Belt asteroids observed by Spitzer (Ryan+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Name Asteroid number, MPC-packed format
7- 12 F6.2 km Dia Diameter
14- 18 F5.2 km e_Dia Uncertainty in Dia
20- 23 F4.2 --- eta Beaming parameter
25- 28 F4.2 --- e_eta Uncertainty in eta
30- 33 F4.2 --- pV Visible albedo
35- 38 F4.2 --- e_pV Uncertainty in pV
40- 43 F4.2 --- pW1 WISE 3.4 micron band albedo
45- 48 F4.2 --- e_pW1 Uncertainty in pW1
50- 53 F4.2 --- pW2 ? WISE 4.5 micron band albedo (1)
55- 58 F4.2 --- e_pW2 ? Uncertainty in pW2
60- 63 F4.1 mag HVMag Absolute HV magnitude
65- 68 F4.2 --- G Photometric slope parameter
70- 74 I5 --- Family ? Associated family identifier from
Masiero et al. (2013, J/ApJ/770/7) (2)
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Note (1): Null if pW2 can not be constrained.
Note (2): Null if the object is not associated to a family.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 04-Apr-2017