J/A+A/630/A50 Combining HCI and RV of nearby stars (Boehle+, 2019)
Combining high-contrast imaging and radial velocities to constrain the
planetary architectures of nearby stars.
Boehle A., Quanz S.P., Lovis C., Segransan D., Udry S., Apai D.
<Astron. Astrophys. 630, A50 (2019)>
=2019A&A...630A..50B 2019A&A...630A..50B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; Radial velocities
Keywords: techniques: high angular resolution -
planets and satellites: general - infrared: planetary systems -
solar neighborhood - techniques: radial velocities
Abstract:
Nearby stars are prime targets for exoplanet searches and
characterization using a variety of detection techniques. Combining
constraints from the complementary detection methods of high-contrast
imaging (HCI) and radial velocity (RV) can further constrain the
planetary architectures of these systems because these methods place
limits at different regions of the companion mass and semi-major axis
parameter space. Compiling a census of the planet population in the
solar neighborhood is important to inform target lists for future
space missions that will specifically target nearby stars to search
for Earth analogs.
We aim to constrain the planetary architectures from the combination
of HCI and RV data for six nearby stars within 6pc: tau Ceti,
Kapteyn;s star, AX Mic, 40 Eri, HD 36395, and HD 42581. We explored
where HCI adds information to constraints from the long-term RV
monitoring data for these stars.
We compiled the sample from stars with available archival VLT/NACO HCI
data at L' band (3.8um), where we expect substellar companions to
be brighter for the typically older ages of nearby field stars
(>1Gyr). The NACO data were fully reanalyzed using the
state-of-the-art direct imaging pipeline PynPoint and combined with RV
data from HARPS, Keck/HIRES, and CORALIE. A Monte Carlo approach was
used to assess the completeness in the companion mass and semi-major
axis parameter space from the combination of the HCI and RV data sets.
We find that the HCI data add significant information to the RV
constraints, increasing the completeness for certain companions masses
and semi-major axes by up to 68-99% for four of the six stars in
our sample, and by up to 1-13% for the remaining stars. The
improvements are strongest for intermediate semi-major axes
(15-40AU), corresponding to the semi-major axes of the ice giants in
our own solar system. The HCI mass limits reach 5-20MJup in the
background-limited regime, depending on the age of the star.
Through the combination of HCI and RV data, we find that stringent
constraints can be placed on the possible substellar companions in
these systems. Applying these methods systematically to nearby stars
will quantify our current knowledge of the planet population in the
solar neighborhood and inform future observations.
Description:
The table contain all the radial velocity (RV) data used to constrain
the planetary architecture of these 6 nearby stars. The data were
first binned on a nightly basis and then calibrated for secular
acceleration and instrumental offsets as described in Sec. 2.2 of the
paper. Each data release for each instrument (e.g., HARPS03 and
HARPS15 for the HARPS instrument) is listed separately as each data
release was calibrated independently.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 37 6 List of studied stars
table.dat 63 2170 Radial velocities
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Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Star name
10- 11 I2 h RAh Simbad Hour of Right Ascension (J2000.0)
13- 14 I2 min RAm Simbad Minute of Right Ascension (J2000.0)
16- 20 F5.2 s RAs Simbad Second of Right Ascension (J2000.0)
22 A1 --- DE- Simbad Sign of the Declination (J2000.0)
23- 24 I2 deg DEd Simbad Degree of Declination (J2000.0)
26- 27 I2 arcmin DEm Simbad Arcminute of Declination (J2000.0)
29- 32 F4.1 arcsec DEs Simbad Arcsecond of Declination (J2000.0)
34- 37 I4 --- Nobs Number of radial velocity measurements
in table.dat
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Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Star name
10- 21 F12.6 d MJD MJD date of radial velocity data point
25- 34 F10.6 m/s RV Calibrated radial velocity
41- 48 F8.6 m/s e_RV Error in RV
57- 63 A7 --- Inst Instrument used for RV measurement (1)
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Note (1): Instruments are COR07, COR14, COR98, HARPS03, HARPS15 and HIRES.
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Acknowledgements:
Anna Boehle, boehlea(at)phys.ethz.ch
(End) Anna Boehle [ETH Zurich, Switzerland], Patricia Vannier [CDS] 23-Aug-2019