J/A+A/640/A109 VLA and XMM-EPIX maps of M83 (Wezgowiec+, 2020)
Hot gas heating via magnetic arms in spiral galaxies. The case of M 83.
Wezgowiec M., Ehle M., Soida M., Dettmar R.-J., Beck R., Urbanik M.
<Astron. Astrophys. 640, A109 (2020)>
=2020A&A...640A.109W 2020A&A...640A.109W (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Radio sources ; X-ray sources ;
Polarization
Keywords: galaxies: individual: M 83 - galaxies: ISM - galaxies: spiral -
galaxies: magnetic fields - magnetic reconnection - X-rays: galaxies
Abstract:
Reconnection heating has been considered as a potential source of the
heating of the interstellar medium. In some galaxies, significant
polarised radio emission has been found between the spiral arms. This
emission has a form of 'magnetic arms' that resembles the spiral
structure of the galaxy. Reconnection effects could convert some of
the energy of the turbulent magnetic field into the thermal energy of
the surrounding medium, leaving more ordered magnetic fields, as is
observed in the magnetic arms.
Sensitive radio and X-ray data for the grand-design spiral galaxy M 83
are used for a detailed analysis of the possible interactions of
magnetic fields with hot gas, including a search for signatures of gas
heating by magnetic reconnection effects.
Magnetic field strengths and energies derived from the radio emission
are compared with the parameters of the hot gas calculated from the
model fits to sensitive X-ray spectra of the hot gas emission.
The available X-ray data allowed us to distinguish two thermal
components in the halo of M 83. We found slightly higher average
temperatures of the hot gas in the interarm regions, which results in
higher energies per particle and is accompanied by a decrease in the
energy density of the magnetic fields.
The observed differences in the energy budget between the spiral arms
and the interarm regions suggest that, similar to the case of another
spiral galaxy NGC 6946, we may be observing hints for gas heating by
magnetic reconnection effects in the interarm regions. These effects,
which act more efficiently on the turbulent component of the magnetic
field, are expected to be stronger in the spiral arms. However, with
the present data it is only possible to trace them in the interarm
regions, where the star formation and the resulting turbulence is low.
Description:
We present the radio and X-ray data for M83 in FITS format (m83_):
1. VLA data: 6cm - total power (I), polarised intensity (PI),
polarisation angle (PA), degree of polarisation (DEG)
2. VLA data: 3cm - total power (I), polarised intensity (PI),
polarisation angle (PA), degree of polarisation (DEG)
3. VLA data: Rotation Measure between 3 and 6cm (RM)
4. VLA data: Depolarisation map between 3 and 6cm (DP)
5. XMM-Newton EPIC emission in the energy band 0.2-1 keV (xsf) - total (t)
and ghosted (g)
6. XMM-Newton EPIC emission in the energy band 1-2keV (xmd) - total (t)
and ghosted (g)
7. XMM-Newton EPIC emission in the energy band 0.2-2 keV (xtot)
8. XMM-Newton EPIC hardness ratio map between
the energy bands 0.2-1 and 1-2 keV (xhr) - total (t) and ghosted (g)
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
13 37 00.92 -29 51 56.7 M83 = NGC 5236
-----------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 152 17 List of fits maps
fits/* . 17 Individual fits maps
--------------------------------------------------------------------------------
See also:
J/A+A/410/53 : M83 X-ray sources (Soria+, 2003)
J/A+A/553/A7 : XMM sources in M83 (NGC5236) (Ducci+, 2013)
J/A+A/578/A100 : Infrared massive stellar content of M83 (Williams+, 2015)
J/AJ/136/479 : IRAC observations of M83 extended UV disk (Dong+, 2008)
J/ApJS/212/21 : A deep Chandra ACIS survey of M83 (Long+, 2014)
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- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 39 A10 "date" Obs.date Observation date
41- 47 F7.5 GHz Freq ? Observed frequency for VLA maps
49- 52 I4 Kibyte size Size of FITS file
54- 65 A12 --- FileName Name of FITS file, in subdirectory fits
67-153 A87 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Acknowledgements:
Marek Wezgowiec, markmet(at)oa.uj.edu.pl
(End) Patricia Vannier [CDS] 20-Jul-2020