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. =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, Q{phi}(r)/I{star}, and measure different profile peak radii for different bands because of the wavelength dependence of the dust opacity. The disk-integrated polarization is Q{phi}/I{star}=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{star}=3.9+/-0.5% in the J band, and the fractional polarization is p{phi}=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 {Lambda}{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 {omega}~0.5, scattering asymmetry g~0.5, and scattering polarization p_max_~0.7 for the dust. Because p_{phi}_ and {Lambda}{I} depend predominantly on dust scattering parameters and only weakly on the disk geometry, these parameters define tight relations for the dust scattering parameters {omega} and p_max_ and {omega} and g. The positive R to J band color for the polarized reflectivity, (Q{phi}/I{star})_J_~1.64x(Q{phi}/I{star})_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 Q{phi} and I{star} for all three wavelengths. The averaged images for Q{phi} and I{star} for R, J, and H band as presented in Figure 1. Images are cut to 3*3 arcsec size. Objects: ----------------------------------------------------------------------- RA (2000) DE Designation(s) ----------------------------------------------------------------------- 16 04 21.65 -21 30 28.5 2MASS J16042165-2130284 = RX J1604.3-2130A ----------------------------------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file list.dat 114 3 List of fits images fits/* . 3 Individual fits images -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- Acknowledgements: Jie Ma, jma(at)phys.ethz.ch ================================================================================ (End) Patricia Vannier [CDS] 21-Jun-2023