J/A+A/680/A114 FITS images of SPHERE protoplanetary disks (Ren+, 2023)
Protoplanetary disks in Ks-band total intensity and polarized light.
Ren B.B., Benisty M., Ginski C., Tazaki R., Wallack N.L., Milli J.,
Garufi A., Bae J., Facchini S., Menard F., Pinilla P., Swastik C.,
Teague R., Wahhaj Z.
<Astron. Astrophys. 680, A114 (2023)>
=2023A&A...680A.114R 2023A&A...680A.114R (SIMBAD/NED BibCode)
ADC_Keywords: Stars, normal ; Interstellar medium ; Optical ; Infrared
Keywords: techniques: high angular resolution - techniques: image processing -
planets and satellites: detection - protoplanetary disks -
stars: imaging
Abstract:
The diverse morphology among protoplanetary disks may result from
planet-disk interactions, suggesting the presence of planets
undergoing formation. The characterization of disks can provide
information on the formation environments of planets. To date, most
imaging campaigns have probed the polarized light from disks, which is
only a fraction of the total scattered light and not very sensitive to
planetary emission.
We aim to observe and characterize protoplanetary disk systems in the
near-infrared in both polarized and total intensity light to carry out
an unprecedented study of the dust scattering properties of disks, as
well as of any possible planetary companions.
Using the star-hopping mode of the SPHERE instrument at the Very Large
Telescope, we observed 29 young stars hosting protoplanetary disks and
their reference stars in the Ks-band polarized light. We extracted
disk signals in total intensity by removing stellar light using the
corresponding reference star observations, by adopting the data
imputation concept with sequential non-negative matrix factorization
(DI-sNMF). For well-recovered disks in both polarized and total
intensity light, we parameterized the polarization fraction phase
functions using a scaled beta distribution. We investigated the
empirical DI-sNMF detectability of disks using logistic regression.
For systems with SPHERE data in the Y, J, and H bands, we have
summarized their polarized color at an approximately 90° scattering
angle.
We obtained high-quality disk images in total intensity for 15 systems
and in polarized light for 23 systems. The total intensity
detectability of disks primarily depends on the host star brightness,
which determines adaptive-optics control ring imagery and thus stellar
signals capture using DI-sNMF. The peak of polarization fraction
tentatively correlates with the peak scattering angle, which could be
reproduced using certain composition for compact dust, yet more
detailed modeling studies are needed. Most of the disks are blue in
polarized J-Ks color and the fact that they are relatively redder
as stellar luminosity increases indicates larger scatterers.
High-quality disk imagery in both total intensity and polarized light
allows for disk characterizations in the polarization fraction.
Combining these techniques reduces the confusion between the disk and
planetary signals.
Description:
We observed 29 disks between November 27 and July 7, 2020, using
VLT/SPHERE in the star-hopping mode in Ksband with the Infra-Red
Dual-band Imager and Spectrograph (IRDIS). The data were obtained
through six programs: 0103.C-0470, 105.209E, 105.20HV, 106.21HJ, and
108.22EE (PI: M. Benisty), and 105.20JB (PI: M. Keppler).
FITS files of disk images in SPHERE/IRDIS (Ks-band) from the Very
Large Telescope.
The stars are located at the mathematical centers of the arrays.
The units are in counts per pixel for Qphi and Uphi data.
The polarization fraction images are unitless.
Divide Qphi by polarization fraction to obtain total intensity images.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 51 29 List of studied stars
fig9.dat 84 26 Polarized color at ∼90° scattering angle
list.dat 160 129 List of fits images
fits/* . 129 Individual fits images
fig5.dat 60 3006 RDI contrast curves
fige1.dat 60 7712 ADI contrast curves
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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- 10 A10 --- Name Star name
12- 13 I2 h RAh right ascension (J2000)
15- 16 I2 min RAm right ascension (J2000)
18- 22 F5.2 s RAs right ascension (J2000)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 35 F5.2 arcsec DEs Declination (J2000)
37- 40 A4 --- Fig5 Indicates data in fig5.dat
42- 45 A4 --- Fig9 Indicates data in fig9.dat
47- 51 A5 --- FigE1 Indicates data in fige1.dat
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Byte-by-byte Description of file: fig9.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Star name
12- 13 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
18- 22 F5.2 s RAs Right ascension (J2000)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 35 F5.2 arcsec DEs Declination (J2000)
37- 41 F5.2 Lsun Lstar Stellar luminosity
43- 46 F4.2 Lsun e_Lstar Error of stellar luminosity
48- 52 F5.3 mag Y-Kdisk ?=- Disk color in Y-K band
54- 58 F5.3 mag e_Y-Kdisk ?=- Error of disk color in Y-K band
60- 65 F6.3 mag J-Kdisk ?=- Disk color in J-K band
67- 71 F5.3 mag e_J-Kdisk ?=- Error of disk color in J-K band
73- 78 F6.3 mag H-Kdisk ?=- Disk color in H-K band
80- 84 F5.3 mag e_H-Kdisk ?=- Error of disk color in H-K band
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Star name
12- 13 I2 h RAh right ascension (J2000)
15- 16 I2 min RAm right ascension (J2000)
18- 22 F5.2 s RAs right ascension (J2000)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 35 F5.2 arcsec DEs Declination (J2000)
37- 42 F6.4 arcsec/pix scale Scale of the image
44- 46 I3 --- Nx Number of pixels along X-axis
48- 50 I3 --- Ny Number of pixels along Y-axis
52- 61 A10 "datime" Obs.date Observation date
63- 65 I3 Kibyte size Size of FITS file
67-105 A39 --- FileName Name of FITS file, in subdirectory fits
107-160 A54 --- Title Title of the FITS file
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Byte-by-byte Description of file: fig5.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Star name
12- 21 A10 "date" Date Observation date
23- 34 E12.7 arcsec Sep Separation
36- 47 E12.7 --- Cont Ks-band 5σ contrast with RDI
(in {DELTA}mag units)
49- 60 E12.7 Mjup Mass ?=- 5σ mass limit
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Byte-by-byte Description of file: fige1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Star name
12- 21 A10 "date" Date Observation date
23- 34 E12.7 arcsec Sep Angular separation
36- 47 E12.7 --- Cont Ks-band 5σ contrast with ADI
(in {DELTA}mag units)
49- 60 E12.7 Mjup Mass ?=- 5σ mass limit
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Acknowledgements:
Bin Ren, bin.ren(at)oca.eu
(End) Patricia Vannier [CDS] 31-Oct-2023