J/ApJS/243/12 Colors of the Outer Solar System Origins Survey (Schwamb+, 2019)
Col-OSSOS: the Colors of the Outer Solar System Origins Survey.
Schwamb M.E., Fraser W.C., Bannister M.T., Marsset M., Pike R.E.,
Kavelaars J.J., Benecchi S.D., Lehner M.J., Wang S.-Y., Thirouin A.,
Delsanti A., Peixinho N., Volk K., Alexandersen M., Chen Y.-T., Gladman B.,
Gwyn S.D.J., Petit J.-M.
<Astrophys. J. Suppl. Ser., 243, 12 (2019)>
=2019ApJS..243...12S 2019ApJS..243...12S
ADC_Keywords: Minor planets; Colors; Photometry, ugriz; Magnitudes, absolute;
Surveys
Keywords: Kuiper belt: general ; minor planets, asteroids: general ;
planets and satellites: dynamical evolution and stability ;
planets and satellites: formation ; surveys
Abstract:
The Colours of the Outer Solar System Origins Survey is acquiring
near-simultaneous g, r, and J photometry of unprecedented precision
with the Gemini North Telescope, targeting nearly 100 trans-Neptunian
objects (TNOs) brighter than mr=23.6mag discovered in the Outer
Solar System Origins Survey. Combining the optical and near-infrared
photometry with the well-characterized detection efficiency of the
Colours of the Outer Solar System Origins Survey target sample will
provide the first flux-limited compositional dynamical map of the
outer solar system. In this paper, we describe our observing strategy
and detail the data reduction processes we employ, including
techniques to mitigate the impact of rotational variability. We
present optical and near-infrared colors for 35 TNOs. We find two
taxonomic groups for the dynamically excited TNOs, the neutral and red
classes, which divide at g-r∼0.75. Based on simple albedo and orbital
distribution assumptions, we find that the neutral class outnumbers
the red class, with a ratio of 4:1 and potentially as high as 11:1.
Including in our analysis constraints from the cold classical objects,
which are known to exhibit unique albedos and r-z colors, we find that
within our measurement uncertainty our observations are consistent
with the primordial solar system protoplanetesimal disk being neutral
class dominated, with two major compositional divisions in grJ color
space.
Description:
All the Colors of the Outer Solar System Origins Survey (Col-OSSOS)
targets are drawn from the sample of over 800 trans-Neptunian objects
(TNOs) and Centaurs (mr=21.8-25.2mag; 3.6<Hr<14.5mag) found by the
OSSOS (Bannister+ 2016, J/AJ/152/70 ; 2018ApJS..236...18B 2018ApJS..236...18B), a survey
with well-characterized survey biases. OSSOS was a wide-field r-band
survey with the 3.58m Canada-France-Hawaii Telescope's (CFHT)
MegaPrime square-degree field-of-view (FOV) imager (MegaCam).
Operating from 2013 to 2017, OSSOS searched eight 20deg2 regions
(blocks) of sky, at locations where resonant TNOs come to perihelion
and become optimally detectable.
The Col-OSSOS sample consists of the 96 TNOs brighter than or equal to
mr=23.6 in the 13AE, 13AO, 13BL, 14BH, and 15BS OSSOS blocks.
Col-OSSOS photometry for the 35 TNOs from 13BL (o3l-designated
targets) and 14BH (o4h-designated targets) blocks is reported in this
paper. 13BL block is a 20deg2 region overlaying the invariant plane,
centered at RA=0:54, DE=+3:50. 14BH block is a 21deg2 region
2°-5° off the invariant plane, centered at RA=1:35, DE=+13:28.
The Gemini observations were acquired as described in Section 3.3,
during 2014-2015 (under programs GN-2014B-LP-1, GN-2015A-LP-1, and
GN-2015B-LP-1), with some minor exceptions described in Section 5.2.
Table 3 gives a detailed summary of the GMOS-N and NIRI observations
for each target TNO in g-, r-, and J-band.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 109 37 Orbital parameters and optical and near-infrared
colors of the o3l and o4h Col-OSSOS
trans-Neptunian object (TNO) sample
table3.dat 115 395 o3l and o4h Col-OSSOS TNO sample observations
fits/* . 393 Individual reduced FITS files described in Table 3
--------------------------------------------------------------------------------
See also:
B/astorb : Orbits of Minor Planets (Bowell+ 2014)
J/AJ/130/873 : Properties of BQS objects in the SDSS DR3 area (Jester+, 2005)
J/AJ/135/55 : NIR spectra of Centaurs & Kuiper Belt objects (Barkume+, 2008)
J/A+A/505/1283 : (84922) 2003 VS2 differential light curve (Duffard+, 2009)
J/A+A/546/A115 : Colors of minor bodies in outer solar system (Hainaut+, 2012)
J/A+A/546/A86 : R absolute magnitudes of Kuiper Belt objects (Peixinho+, 2012)
J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)
J/A+A/577/A35 : Visible colors of Centaurs and KBOs (Peixinho+, 2015)
J/AJ/152/70 : Outer Solar System Origins Survey (OSSOS) (Bannister+, 2016)
J/AJ/152/221 : New extreme trans-Neptunian objects (Sheppard+, 2016)
J/AJ/157/94 : Col-OSSOS: outer solar system objects data (Marsset+, 2019)
J/AJ/157/120 : TNOs & Centaurs observed within the DES (Banda-Huarca+, 2019)
J/AJ/157/228 : Cold Classical TNOs: LCs + rotational data (Thirouin+, 2019)
http://archive.gemini.edu/ : Gemini Observatory Archive search page
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- MPC MPC designation (1)
12- 18 A7 --- Flag Source flag(s) (2)
20- 26 A7 --- OSSOS OSSOS survey designation (3)
28- 33 F6.2 au a [23.2/130] Orbital semi-major axis
35- 39 F5.3 --- e [0.01/0.8] Orbital eccentricity
41- 45 F5.2 deg i [0.7/29.6] Orbital inclination
47- 51 F5.2 au Delta [15.6/49.7] Geocentric distance, Δ (4)
53- 57 F5.2 au rh [16.3/50.5] Heliocentric distance (4)
59- 63 F5.2 mag rmag [22.3/24.2] Mean SDSS r band magnitude (5)
65- 68 F4.2 mag e_rmag [0/0.3] Uncertainty in rmag
70- 74 F5.2 mag HrMag [5.8/11.4] Absolute magnitude H in Flt (Hr)
76- 79 A4 --- Class Orbital classification (6)
81- 84 F4.2 mag (g-r) [0.5/1.1] SDSS g-r color index
86- 89 F4.2 mag e_(g-r) [0.01/0.04] Uncertainty in (g-r)
91- 94 F4.2 mag (r-J) [0.9/2] SDSS r band - MKO J band color index
96- 99 F4.2 mag e_(r-J) [0.04/0.2] Uncertainty in (r-J)
101-104 F4.2 mag (r-z) [0.3/0.8]? SDSS r-z color index
106-109 F4.2 mag e_(r-z) [0.02/0.09]? Uncertainty in (r-z)
--------------------------------------------------------------------------------
Note (1): Those targets with two observation epochs have a separate entry
for the color measurements derived at each epoch, ordered
chronologically.
Note (2): Source flags as follows:
A = Targets with previously published optical colors in
Pike+ (2017AJ....154..101P 2017AJ....154..101P) reprocessed here using the latest version
of TRIPPy (Fraser et al. 2016AJ....151..158F 2016AJ....151..158F), the most recent data
analysis pipeline, and improved SDSS color terms. Additional Subaru
r and z photometry for some of the highlighted targets is reported
in Pike et al. (2017AJ....154..101P 2017AJ....154..101P) Only (r-z) colors obtained from
Gemini observing sequences if available are reported here;
B = Telescope tracked nonsidereally at the TNO's rate of motion on-sky;
C = Targets with previously published optical spectral slopes in
Fraser+ (2017NatAs...1E..88F 2017NatAs...1E..88F) reprocessed here using the latest
version of TRIPPy (Fraser+ 2016AJ....151..158F 2016AJ....151..158F) the most
recent data analysis pipeline, and improved SDSS color terms;
D = Confirmed as a binary in Fraser et al. (2017NatAs...1E..88F 2017NatAs...1E..88F);
E = 2014B observations;
F = Photometry includes CFHT measurements;
G = 2015B observations;
H = Orbit consistent with the Haumea collisional family cluster.
Note (3): OSSOS survey designations as in Bannister+ (2016, J/AJ/152/70).
Note (4): Geometric parameters and derived HrMag are reported for the time
of the Col-OSSOS observation; see Table 3.
Note (5): Mean rmag is the mean of the measured Col-OSSOS r-band
photometry. Values for individual frames are reported in Table 3.
Note (6): Orbit class: dynamical classification of barycentric orbits
from a 10Myr integration. See Bannister et al. (2018ApJS..236...18B 2018ApJS..236...18B)
for further details.
cen = Centaur;
sca = scattering disk;
cla = classical belt;
N:M = mean motion resonance with Neptune. An "I" after the resonant
identifier signifies an insecure resonance classification.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- MPC MPC designation
12- 18 A7 --- OSSOS OSSOS designation (1)
20- 30 A11 --- ID ColOSSOS Header identifier (2)
32- 50 A19 --- File Reduced FITS filename (3)
52- 59 A8 --- Filt Filter (J; g.MP9402; r.MP9602; g_G0301; r_G0303
or z_G0304)
61- 71 F11.5 d MJD [56891.4/57390.4] Modified Julian Date,
JD-2400000.5
73- 78 F6.3 mag mag1 [20.8/25.3] Magnitude in Filt
80- 84 F5.3 mag e_mag1 [0.01/0.2] Uncertainty in mag1
86- 91 F6.3 mag zpt1 [23.7/32.8] Zeropoint
93- 97 F5.3 mag e_zpt1 [0.001/0.02] Uncertainty in zpt1
99-104 F6.3 mag mag2 [22.3/25.4]? SDSS magnitude (see Appendix A3 for
the photometric calibration to SDSS photometric
system)
106-110 F5.3 mag e_mag2 [0.01/0.3]? Uncertainty in mag2
112-115 I4 s Exp [200/4800] Exposure time (4)
--------------------------------------------------------------------------------
Note (1): OSSOS survey designations as in Bannister+ (2016, J/AJ/152/70).
Note (2): The Header ID column reflects the OBJECT keyword in the Gemini/CFHT
raw FITS headers, as the internal survey designation for target TNOs on
occasion may have changed over the course of the OSSOS survey.
Note (3): The reduced FITS files produced in this analysis are available for
download at the Canadian Astronomy Data Centre, doi:10.11570/19.0009;
DOI: All raw Gemini data files and calibration files associated with these
observations are available via the Gemini Observatory Archive
(http://archive.gemini.edu/). Gemini program IDs for these observations
are GN-2014B-LP-1, GN-2015A-LP-1 and GN-2015B-LP-1. All raw CFHT data
files and calibration files associated with these observations are
available via the CFHT Science Archive
(http://www.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/en/cfht/). CFHT program IDs
for these observations is 15BP05.
Note (4): For J-band, the reported exposure time is the total effective
exposure time of the stacked image
--------------------------------------------------------------------------------
History:
Tables 1 and 3 from electronic version of the journal --
FITS files downloaded at the Canadian Astronomy Data Centre:
http://www.canfar.net/citation/landing?doi=19.0009
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 10-Dec-2019