The first degree-scale starlight-polarization-based tomography map of the magnetized interstellar medium
Artikel i vetenskaplig tidskrift, 2024
We present the first degree-scale tomography map of the dusty magnetized interstellar medium (ISM) from stellar polarimetry and distance measurements. We used the RoboPol polarimeter at Skinakas Observatory to conduct a survey of the polarization of starlight in a region of the sky of about four square degrees. We propose a Bayesian method to decompose the stellar-polarization source field along the distance to invert the three-dimensional (3D) volume occupied by the observed stars. We used this method to obtain the first 3D map of the dusty magnetized ISM. Specifically, we produced a tomography map of the orientation of the plane-of-sky component of the magnetic field threading the diffuse, dusty regions responsible for the stellar polarization. For the targeted region centered on Galactic coordinates (l, b) (103.3, 22.3), we identified several ISM clouds. Most of the lines of sight intersect more than one cloud. A very nearby component was detected in the foreground of a dominant component from which most of the polarization signal comes and which we identified as being an intersection of the wall of the Local Bubble and the Cepheus Flare. Farther clouds, with a distance of up to 2 kpc, were similarly detected. Some of them likely correspond to intermediate-velocity clouds seen in H I spectra in this region of the sky. We found that the orientation of the plane-of-sky component of the magnetic field changes along distance for most of the lines of sight. Our study demonstrates that starlight polarization data coupled to distance measures have the power to reveal the great complexity of the dusty magnetized ISM in 3D and, in particular, to provide local measurements of the plane-of-sky component of the magnetic field in dusty regions. This demonstrates that the inversion of large data volumes, as expected from the PASIPHAE survey, will provide the necessary means to move forward in the modeling of the Galactic magnetic field and of the dusty magnetized ISM as a contaminant in observations of the cosmic microwave background polarization.
ISM: structure
ISM: magnetic fields
Dust, extinction
Polarization
Methods: statistical
Författare
V. Pelgrims
Panepistimio Kritis
Idryma Technologias kai Erevnas (FORTH)
Université libre de Bruxelles (ULB)
N. Mandarakas
Idryma Technologias kai Erevnas (FORTH)
Panepistimio Kritis
R. Skalidis
California Institute of Technology (Caltech)
Konstantinos Tassis
Idryma Technologias kai Erevnas (FORTH)
Panepistimio Kritis
Georgia Virginia Panopoulou
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
V. Pavlidou
Idryma Technologias kai Erevnas (FORTH)
Panepistimio Kritis
D. Blinov
Idryma Technologias kai Erevnas (FORTH)
Panepistimio Kritis
S. Kiehlmann
Idryma Technologias kai Erevnas (FORTH)
Panepistimio Kritis
S. E. Clark
Stanford University
Kavli Institute for Particle Astrophysics and Cosmology
Brandon S. Hensley
California Institute of Technology (Caltech)
S. Romanopoulos
Panepistimio Kritis
Idryma Technologias kai Erevnas (FORTH)
A. Basyrov
Universitetet i Oslo
H. K. Eriksen
Universitetet i Oslo
M. Falalaki
Idryma Technologias kai Erevnas (FORTH)
Panepistimio Kritis
T. Ghosh
Homi Bhabha National Institute (HBNI)
Inter-University Centre for Astronomy and Astrophysics
E. Gjerløw
Universitetet i Oslo
J. A. Kypriotakis
Panepistimio Kritis
Idryma Technologias kai Erevnas (FORTH)
S. Maharana
South African Astronomical Observatory
A. Papadaki
Panepistimio Kritis
Idryma Technologias kai Erevnas (FORTH)
Institute of Computer Science Crete
T. J. Pearson
California Institute of Technology (Caltech)
S. B. Potter
University of Johannesburg
South African Astronomical Observatory
A. N. Ramaprakash
Université libre de Bruxelles (ULB)
California Institute of Technology (Caltech)
Inter-University Centre for Astronomy and Astrophysics
A. C.S. Readhead
California Institute of Technology (Caltech)
I. K. Wehus
Universitetet i Oslo
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 684Ämneskategorier
Astronomi, astrofysik och kosmologi
DOI
10.1051/0004-6361/202349015