J/AJ/163/165 NIR spectra of 420 near-Earth objects (Marsset+, 2022)
The Debiased Compositional Distribution of MITHNEOS; Global Match between the
Near-Earth and Main-belt Asteroid Populations, and Excess of D-type Near-Earth
Objects.
Marsset M., DeMeo F.E., Burt B., Polishook D., Binzel R.P., Granvik M.,
Vernazza P., Carry B., Bus S.J., Slivan S.M., Thomas C.A., Moskovitz N.A.,
Rivkin A.S.
<Astron. J., 163, 165 (2022)>
=2022AJ....163..165M 2022AJ....163..165M
ADC_Keywords: Solar system; Minor planets; Spectra, infrared
Keywords: Spectroscopy ; Asteroid surfaces ; Near-Earth objects ; Main
belt asteroids
Abstract:
We report 491 new near-infrared spectroscopic measurements of 420
near-Earth objects (NEOs) collected on the NASA InfraRed Telescope
Facility as part of the MIT-Hawaii NEO Spectroscopic Survey. These
measurements were combined with previously published data from Binzel
et al. and bias-corrected to derive the intrinsic compositional
distribution of the overall NEO population, as well as of
subpopulations coming from various escape routes (ERs) in the asteroid
belt and beyond. The resulting distributions reflect well the overall
compositional gradient of the asteroid belt, with decreasing fractions
of silicate-rich (S- and Q-type) bodies and increasing fractions of
carbonaceous (B-, C-, D- and P-type) bodies as a function of
increasing ER distance from the Sun. The close compositional match
between NEOs and their predicted source populations validates
dynamical models used to identify ERs and argues against any strong
composition change with size in the asteroid belt between ∼5km and
∼100m. A notable exception comes from the overabundance of D-type NEOs
from the 5:2J and, to a lesser extend, the 3:1J and ν6 ERs, hinting
at the presence of a large population of small D-type asteroids in the
main belt. Alternatively, this excess may indicate preferential
spectral evolution from D-type surfaces to C and P types as a
consequence of space weathering, or point to the fact that D-type
objects fragment more often than other spectral types in the NEO
space. No further evidence for the existence of collisional families
in the main belt, below the detection limit of current main-belt
surveys, was found in this work.
Description:
We present 491 new NIR spectra of 420 near-Earth objects (NEOs) mainly
between 100m and 3km in diameter. These observations were collected
for the most part between 2015 January and 2021 February through the
MITHNEOS program, with the exception of 10 spectra acquired earlier
(between 2003 and 2013), but inadvertently never published before.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table7.dat 380 491 Complete tabulation
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See also:
II/118 : UBVRI standards around Celestial Equator (Landolt 1983)
J/ApJ/741/68 : Main Belt asteroids with WISE/NEOWISE. I. (Masiero+, 2011)
J/PASJ/63/1117 : Asteroid catalog using AKARI (AcuA). V1. (Usui+, 2011)
J/AJ/152/63 : NEOWISE reactivation mission; 2nd yr data (Nugent+, 2016)
J/AJ/154/168 : NEOWISE; thermal model fits for NEOs and MBAs (Masiero+, 2017)
J/AJ/156/60 : Thermal model fits for short-arc NEOs NEOWISE (Masiero+, 2018)
J/AJ/158/196 : Near-Earth Object Survey spectroscopy (Devogele+, 2019)
J/AJ/157/94 : Col-OSSOS Prop. outer solar system objects (Marsset+, 2019)
J/ApJS/243/12 : Colors of Outer Solar System Origins Survey (Schwamb+, 2019)
J/A+A/652/A59 : SDSS Solar System Objects (Sergeyev+, 2021)
J/A+A/654/A56 : Largest main belt asteroids data (Vernazza+, 2021)
Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 32 A32 --- File Spectrum filename
34- 39 I6 --- Number [433/531060]? Near-Earth Object Number
41- 50 A10 --- Desig Provisional designation
52- 64 A13 --- Name Name
66- 74 F9.7 au a [0.64/3.36] Semi-major Axis
76- 84 F9.7 --- e [0.03/0.9] Eccentricity
86- 93 F8.5 deg i [0.44/63.8] Inclination
95- 99 F5.2 mag Hmag [9.25/27.7] H Magnitude
101-111 F11.9 --- TJup [2.39/8.5] Jupiter Tisserand
113-118 F6.3 km/s Delta-v [4.1/23.6]? Velocity Change Needed for
Rendez-vous Mission
120-122 A3 --- Hazard? Potentially Hazardous? Yes or No
124-129 A6 --- Taxon Taxonomy
131-137 F7.4 /um Slope [-0.19/1.09] Spectral Slope
139-145 F7.4 --- PC1 [-1.46/1.79] 1st Principal Component (1)
147-153 F7.4 --- PC2 [-0.75/1.2] 2nd Principal Component (1)
155-161 F7.4 --- PC3 [-0.62/0.63] 3rd Principal Component (1)
163-169 F7.4 --- PC4 [-0.31/0.25] 4th Principal Component (1)
171-177 F7.4 --- PC5 [-0.21/0.3] 5th Principal Component (1)
179-182 I4 --- ObsY-S [2003/2021] Start Date Time, year
184-185 I2 --- ObsM-S Start Date Time, month
187-188 I2 --- ObsD-S Start Date Time, day
190-191 I2 --- ObsH-S Start Date Time, hour
193-194 I2 --- Obsm-S Start Date Time, minute
196-200 F5.2 --- ObsS-S Start Date Time, second
202-205 I4 --- ObsY-E [2003/2021] End Date Time, year
207-208 I2 --- ObsM-E End Date Time, month
210-211 I2 --- ObsD-E End Date Time, day
213-214 I2 --- ObsH-E End Date Time, hour
216-217 I2 --- Obsm-E End Date Time, minute
219-223 F5.2 --- ObsS-E End Date Time, second
225-227 I3 h RAh [0/23] Hour of Right Ascension (J2000)
229-230 I2 min RAm Minute of Right Ascension (J2000)
232-235 F4.1 s RAs Second of Right Ascension (J2000)
237-237 A1 --- DE- [-] Sign of the Declination (J2000)
238-239 I2 deg DEd [0/68] Degree of Declination (J2000)
241-242 I2 arcmin DEm Minute of Declination (J2000)
244-245 I2 arcsec DEs Second of Declination (J2000)
247-251 F5.3 --- Amass-S [1/1.97] Start Airmass
253-257 F5.3 --- Amass-E [1/2.17] End Airmass
259-265 F7.2 deg ParAng-S [-178/179] Start Parallactic Angle
267-273 F7.2 deg ParAng-E [-180/180] End Parallactic Angle
275-282 F8.4 s Texp [14.8/120] Exposure Time
284-285 I2 --- Nimages [12/23] Number of Images
287-293 F7.2 s TTexp [466/2760] Total Exposure Time
295-300 F6.4 --- GeoDist [0.001/2.34] Geocentric Distance (AU)
302-306 F5.3 --- SolDist [0.97/3.32] Solar Distance (AU)
308-312 F5.1 deg PhaseAng [1.2/104] Phase Angle
314-317 F4.1 mag Vismag [10.7/18.8] Visual Magnitude
319-326 F8.6 --- P[Hun] [0/0.9] Hungaria Escape Route Probability
328-335 F8.6 --- P[nu6] [0/1] nu6 Escape Route Probability
337-344 F8.6 --- P[Pho] [0/1] Phocaea Escape Route Probability
346-353 F8.6 --- P[3:1J] [0/0.88] 3:1J Escape Route Probability
355-362 F8.6 --- P[5:2J] [0/0.9] 5:2J Escape Route Probability
364-371 F8.6 --- P[2:1J] [0/0.98] 2:1J Escape Route Probability
373-380 F8.6 --- P[JFC] [0/0.54] JFC Escape Route Probability
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Note (1): Principal components were calculated after
removing the spectral slope from the asteroid spectrum.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 11-May-2022