J/A+A/676/A6 RX J1604.3-213010 SPHERE polarimetric images (Ma+, 2023)
Quantitative polarimetry for the transition disk in RX J1604.3-213010.
Ma J,. Schmid H.M., Tschudi C.
<Astron. Astrophys. 676, A6 (2023)>
=2023A&A...676A...6M 2023A&A...676A...6M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, emission ; Polarization ; Photometry, infrared
Keywords: stars: pre-main sequence - protoplanetary disks -
stars: individual: RX J1604.3-213010 - polarization - scattering
Abstract:
RX J1604 is a dipper source, and the data show different kinds of
variability. However, a detailed analysis of repeated measurements
shows that the results are not affected by dipping events or
atmospheric seeing variations. The bright disk of RX J1604 has a very
simple axisymmetric structure and is therefore well suited as a
benchmark object for accurate photo-polarimetric measurements.
We derive accurate radial disk profiles for the intrinsic polarized
intensity, Qφ(r)/I*, and measure different profile peak radii
for different bands because of the wavelength dependence of the dust
opacity. The disk-integrated polarization is
Qφ/I*=0.92±0.04% for the R band and 1.51±0.11% for the J
band, indicating a red color for the polarized reflectivity of the
disk. The intensity of the disk is I{disk}/I*=3.9±0.5% in the
J band, and the fractional polarization is pφ=38±4% for the J
band and 42±2% for the H band. The comparison with the IR excess for
RX J1604 yields an apparent disk albedo of about
Λ{I}∼0.16±0.08. We also find that previously described
shadows seen in the R band data are likely affected by calibration
errors.
Using dust scattering models for transition disks, We derive
approximate J band values for the scattering albedo ω∼0.5,
scattering asymmetry g∼0.5, and scattering polarization pmax∼0.7 for
the dust. Because pφ and Λ{I} depend predominantly on
dust scattering parameters and only weakly on the disk geometry, these
parameters define tight relations for the dust scattering parameters
ω and pmax and ω and g. The positive R to J band color
for the polarized reflectivity,
(Qφ/I*)J∼1.64x(Qφ/I*)R, is mainly a result of
the wavelength dependence of dust parameters because the scattering
geometry is expected to be very similar for different colors. This
work demonstrates the potential of accurate photo-polarimetric
measurements of the circumstellar disk RX J1604 for the determination
of dust scattering parameters that strongly constrain the physical
properties of the dust.
Description:
The presented SPHERE/ZIMPOL images of RX J1604.3-213010 were taken
with R_PRIM + dichroic filters and the SPHERE/IRDIS images were taken
with J-band and H-band filter, respectively. The images show the
averaged Qφ and I* for all three wavelengths.
The averaged images for Qφ and I* for R, J, and H band as
presented in Figure 1. Images are cut to 3*3 arcsec size.
Objects:
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RA (2000) DE Designation(s)
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16 04 21.65 -21 30 28.5 2MASS J16042165-2130284 = RX J1604.3-2130A
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 114 3 List of fits images
fits/* . 3 Individual fits images
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See also:
J/A+A/598/A43 : 2MASS J16042165-2130284 high-contrast images (Canovas+, 2017)
J/A+A/633/A37 : RXJ1604.3-2130A griz and JHK light curves
(Sicilia-Aguilar+, 2020)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28 I1 --- Nz Number of slices
30- 34 I5 Kibyte size Size of FITS file
36- 49 A14 --- FileName Name of FITS file, in subdirectory fits
51-114 A64 --- Title Title of the FITS file
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Acknowledgements:
Jie Ma, jma(at)phys.ethz.ch
(End) Patricia Vannier [CDS] 21-Jun-2023