J/other/NatAs/6.89 Upper Scorpius members (Miret-Roig+, 2022)
A rich population of free-floating planets in the Upper Scorpius young stellar
association.
Miret-Roig N., Bouy H., Raymond S.N., Tamura M., Bertin E., Barrado D.,
Olivares J., Galli A.B.P., Cuillandre J.-C., Sarro L.M., Berihuete A.,
Huelamo N.
<Nature Astronomy, 6, 89-97 (2022)>
=2022NatAs...6...89M 2022NatAs...6...89M (SIMBAD/NED BibCode)
ADC_Keywords: Associations, stellar ; Photometry, SDSS ; Photometry, infrared ;
Proper motions ; Parallaxes, trigonometric
Keywords: star and planet formation - initial mass function -
solar neighborhood - Upper Scor plus and Ophiuchus
Abstract:
The nature and origin of free-floating planets (FFPs) are still
largely unconstrained because of a lack of large homogeneous samples
to enable a statistical analysis of their properties. So far, most
FFPs have been discovered using indirect methods; microlensing surveys
have proved particularly successful to detect these objects down to a
few Earth masses. However, the ephemeral nature of microlensing events
prevents any follow-up observations and individual characterization.
Several studies have identified FFPs in young stellar clusters and the
Galactic field but their samples are small or heterogeneous in age and
origin. Here we report the discovery of between 70 and 170 FFPs
(depending on the assumed age) in the region encompassing Upper
Scorpius and Ophiuchus, the closest young OB association to the Sun.
We found an excess of FFPs by a factor of up to seven compared with
core-collapse model predictions, demonstrating that other formation
mechanisms may be at work. We estimate that ejection from planetary
systems might have a contribution comparable to that of core collapse
in the formation of FFPs. Therefore, ejections due to dynamical
instabilities in giant exoplanet systems must be frequent within the
first 10Myr of a system's life.
Description:
Here we present a search for FFPs in the 171 deg2 region occupied
mainly by Upper Scorpius (USC) and Ophiuchus (Oph). We selected an
elliptical area centred in (RA=243.5°, Dec=-23.1°) with a
semi-major axis of 8.5° in RA and a semi-minor axis of 6.4° in
Dec where the spatial and temporal coverage of the observations is the
best. This large complex represents the perfect hunting ground to
search for young and nearly coeval FFPs thanks to its proximity
(120-145pc) and youth (1-10Myr). We combined our ground-based
observations in the optical and infrared with wide-field images
available in various public archives (see methods). We processed and
analysed a total of 80818 individual wide-field images acquired with
18 different cameras over the past 20 years to obtain a final
catalogue, the Dynamical Analysis of Nearby ClustErs (DANCe)39
catalogue, containing positions, proper motions and multi-wavelength
photometry (grizyJHK) for more than 26 million objects. We
complemented the DANCe catalogue with the astrometry and photometry of
the Gaia Data Release 2 (Gaia DR2) and Hipparcos catalogues.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
final.dat 492 3455 Final members catalog
hip.dat 319 574 HIP catalog
gdr2.dat 184 7849224 Gaia DR2 catalog
dance.dat 617 26408024 DANCe catalog
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
Byte-by-byte Description of file: final.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID [1/3455] Member identification number
6- 24 I19 --- GaiaDR2 ?=- Gaia DR2 source ID
26- 30 I5 --- HIP ?=- HIP identification number
32- 39 I8 --- GDR2ID ?=- Internal Gaia DR2 ID
41- 48 I8 --- DANCe ?=- DANCe identification number
50 A1 --- memHIP [FT-] HIP member?
52 A1 --- memGDR2 [FT-] Gaia DR2 member?
54 A1 --- memDANCe [FT-] DANCE member?
56- 73 F18.16 --- pHIP ? HIP membership probability
75- 92 F18.16 --- pGDR2 ? Gaia DR2 membership probability
94-111 F18.16 --- pDANCe ? Dance membership probability for
113-130 F18.14 deg RAdeg Right ascension (J2000)
132-150 F19.15 deg DEdeg Declination (J2000)
152-172 F21.19 Msun Mass3Myr ? Mass with 3Myr model
174-194 F21.19 Msun e_Mass3Myr ? rms uncertainty on Mass3Myr
196-216 E21.19 mag AV3Myr ?=- Extinction with 3Myr model
218-236 F19.17 mag e_AV3Myr ? rms uncertainty on e_AV3Myr
238-251 A14 --- Model3Myr 3Myr model name
253-273 F21.19 Msun Mass5Myr ? Mass with 5Myr
275-295 F21.19 Msun e_Mass5Myr ? rms uncertainty on Mass5Myr
297-317 E21.19 mag AV5Myr ?=- Extinction with 5Myr model
319-337 F19.17 mag e_AV5Myr ? rms uncertainty on AV5Myr
339-352 A14 --- Model5Myr 5Myr model name
354-374 F21.19 Msun Mass10Myr ? Mass with of 10Myr
376-396 F21.19 Msun e_Mass10Myr ? rms uncertainty on Mass10Myr
398-418 E21.19 mag AV10Myr ?=- Extinction with 10Myr model
420-438 F19.17 mag e_AV10Myr ? rms uncertainty on AV10Myr
440-453 A14 --- Model10Myr 10Myr model name
455-472 F18.14 kpc Dist ? Distance
474-492 F19.16 kpc e_Dist ?=- rms uncertainty on of e_distance
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Byte-by-byte Description of file: hip.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- HIP HIP identification number
7- 27 E21.15 --- Ppin0.5 Membership probability obtained with pin=0.5
29- 49 E21.15 --- Ppin0.6 Membership probability obtained with pin=0.6
51- 71 E21.15 --- Ppin0.7 Membership probability obtained with pin=0.7
73- 93 E21.15 --- Ppin0.8 Membership probability obtained with pin=0.8
95-115 E21.15 --- Ppin0.9 Membership probability obtained with pin=0.9
117-130 F14.10 deg RAdeg Right ascension (J2000)
132-145 F14.10 deg DEdeg Declination DEJ2000
147-154 F8.2 mas/yr pmRA Proper motion along RA, pmRA*cosDE
156-160 F5.2 mas/yr e_pmRA rms uncertainty on pmRA
162-169 F8.2 mas/yr pmDE Proper motion along DE
171-175 F5.2 mas/yr e_pmDE rms uncertainty on pmDE
177-182 F6.2 mas Plx Trigonometric parallax
184-188 F5.2 mas e_Plx rms uncertainty on Plx
190-194 F5.2 --- DE:RA [-1/1]? Correlation, DE/RA*cosDE
196-200 F5.2 --- Plx:RA [-1/1]? Correlation, Plx/RA*cosDE
202-206 F5.2 --- Plx:DE [-1/1]? Correlation, Plx/DE
208-212 F5.2 --- pmRA:RA [-1/1]? Correlation, pmRA/RA*cosDE
214-218 F5.2 --- pmRA:DE [-1/1]? Correlation, pmRA/DE
220-224 F5.2 --- pmRA:Plx [-1/1]? Correlation, pmRA/Plx
226-230 F5.2 --- pmDE:RA [-1/1]? Correlation, pmDE/RA*cosDE
232-236 F5.2 --- pmDE:DE [-1/1]? Correlation, pmDE/DE
238-242 F5.2 --- pmDE:Plx [-1/1]? Correlation, pmDE/Plx
244-248 F5.2 --- pmDE:pmRA [-1/1]? Correlation, pmDE/pmRA
250-254 F5.2 mag Vmag Johnson V magnitude
256-261 F6.3 mag BTmag ?=- Mean BT magnitude
263-267 F5.3 mag e_BTmag ?=- rms uncertainty on BTmag
269-274 F6.3 mag VTmag ?=- Mean VT magnitude
276-280 F5.3 mag e_VTmag ?=- rms uncertainty on VTmag
282-287 F6.3 mag B-V ?=- Johnson B-V colour index-V
289-293 F5.3 mag e_B-V ?=- rms uncertainty on B-V
295-299 F5.2 mag V-I ?=- Johnson V-I colour index
300-304 F5.2 mag e_V-I ?=- rms uncertainty on V-I
306-312 F7.4 mag Hpmag Median magnitude in Hipparcos system
314-319 E6.4 mag e_Hpmag rms uncertainty on Hpmag
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Byte-by-byte Description of file: gdr2.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- GDR2ID Internal ID
(Should Not be used for identification)
10- 30 E21.15 --- Ppin0.5 Membership probability obtained with pin=0.5
32- 52 E21.15 --- Ppin0.6 Membership probability obtained with pin=0.6
54- 74 E21.15 --- Ppin0.7 Membership probability obtained with pin=0.7
76- 96 E21.15 --- Ppin0.8 Membership probability obtained with pin=0.8
98-118 E21.15 --- Ppin0.9 Membership probability obtained with pin=0.9
120-138 I19 --- GaiaDR2 Gaia DR2 source ID
140-154 F15.11 deg RAdeg Gaia DR2 Right ascension (ICRS) at Ep=2015.5
156-161 F6.4 mas e_RAdeg Gaia DR2 Standard error of right ascension
163-177 F15.11 deg DEdeg Gaia DR2 Declination (ICRS) at Ep=2015.5
179-184 F6.4 mas e_DEdeg Gaia DR2 Standard error of declination
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Byte-by-byte Description of file: dance.dat
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Bytes Format Units Label Explanations
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1- 11 E11.8 --- DANCe [14.0/40879795.0] DANCe identification number
13- 33 E21.17 --- Ppin0.5 Membership probability obtained with pin=0.5
35- 55 E21.17 --- Ppin0.6 Membership probability obtained with pin=0.6
57- 77 E21.17 --- Ppin0.7 Membership probability obtained with pin=0.7
79- 99 E21.17 --- Ppin0.8 Membership probability obtained with pin=0.8
101-121 E21.17 --- Ppin0.9 Membership probability obtained with pin=0.9
123-140 F18.14 deg RAdeg Right ascension (J2000)
142-162 E21.19 mas e_RAdeg rms uncertainty on RAdeg
164-182 F19.15 deg DEdeg Declination (J2000)
184-204 E21.19 mas e_DEdeg rms uncertainty on DEdeg
206-227 E22.19 mas/yr pmRA Proper motion along RA, pm RA*cosDE
229-239 F11.8 mas/yr e_pmRA rms uncertainty on pmRA
241-262 E22.19 mas/yr pmDE Proper motion along DE
264-274 F11.8 mas/yr e_pmDE rms uncertainty on pmDE
276-282 E7.4 --- pmRADEcor ?=- Correlation between proper motion in
right ascension and proper motion
in declination
284-301 F18.15 mag gmag ?=99 Pan-STARRS PS1 g magnitude
303-323 F21.18 mag e_gmag ?=99 rms uncertainty on gmag
325-343 F19.15 mag rmag ?=99 Pan-STARRS PS1 r magnitude
345-365 F21.18 mag e_rmag ?=99 rms uncertainty on rmag
367-385 F19.16 mag imag ?=99 Pan-STARRS PS1 i magnitude
387-407 F21.18 mag e_imag ?=99 rms uncertainty on imag
409-427 F19.16 mag zmag ?=99 Pan-STARRS PS1 z magnitude
429-449 F21.18 mag e_zmag ?=99 rms uncertainty on zmag
451-469 F19.16 mag Ymag ?=99 Pan-STARRS PS1 Y magnitude
471-491 F21.18 mag e_Ymag ?=99 rms uncertainty on Ymag
493-511 F19.16 mag Jmag ?=99 2MASS J magnitude
513-533 F21.18 mag e_Jmag ?=99 rms uncertainty on Jmag
535-553 F19.16 mag Hmag ?=99 2MASS H magnitude
555-575 F21.18 mag e_Hmag ?=99 rms uncertainty on Hmag
577-595 F19.16 mag Ksmag ?=99 2MASS Ks magnitude
597-617 F21.18 mag e_Ksmag ?=99 rms uncertainty on Ksmag
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Acknowledgements:
Nuria Miret Roig, nuria.miret.roig(at)univie.ac.at
(End) Patricia Vannier [CDS] 29-Nov-2021