2019A&A...628L...3H


Query : 2019A&A...628L...3H

2019A&A...628L...3H - Astronomy and Astrophysics, volume 628, L3-3 (2019/8-1)

Warped diffusive radio halo around the quiescent spiral edge-on galaxy NGC 4565.

HEESEN V., WHITLER L., SCHMIDT P., MISKOLCZI A., SRIDHAR S.S., HORELLOU C., BECK R., GURKAN G., SCANNAPIECO E., BRUGGEN M., HEALD G.H., KRAUSE M., PALADINO R., NIKIEL-WROCZYNSKI B., WILBER A. and DETTMAR R.-J.

Abstract (from CDS):


Context. Cosmic rays play a pivotal role in launching galactic winds, particularly in quiescently star-forming galaxies where the hot gas alone is not sufficient to drive a wind. Except for the Milky Way, not much is known about the transport of cosmic rays in galaxies.
Aims.In this Letter, we present low-frequency observations of the nearby edge-on spiral galaxy NGC 4565 using the LOw-Frequency ARray (LOFAR). With our deep 144 MHz observations, we obtain a clean estimate of the emission originating from old cosmic-ray electrons (CRe), which is almost free from contamination by thermal emission.
Methods. We measured vertical profiles of the non-thermal radio continuum emission that we fitted with Gaussian and exponential functions. The different profile shapes correspond to 1D cosmic-ray transport models of pure diffusion and advection, respectively. Results. We detect a warp in the radio continuum that is reminiscent of the previously known HI warp. Because the warp is not seen at GHz-frequencies in the radio continuum, its minimum age must be about 100Myr. The warp also explains the slight flaring of the thick radio disc that can otherwise be well described by a Gaussian profile with an FWHM of 65 arcsec (3.7kpc).Conclusions. The diffusive radio halo together with the extra-planar X-ray emission may be remnants of enhanced star-forming activity in the past where the galaxy had a galactic wind, as GHz-observations indicate only a weak outflow in the last 40Myr. NGC 4565 could be in transition from an outflow- to an inflow-dominated phase.

Abstract Copyright: © ESO 2019

Journal keyword(s): galaxies: halos - galaxies: individual: NGC 4565 - galaxies: magnetic fields - galaxies: spiral - cosmic rays - radio continuum: galaxies

VizieR on-line data: <Available at CDS (J/A+A/628/L3): list.dat fits/*>

Simbad objects: 7

goto Full paper

goto View the references in ADS

Number of rows : 7
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 M 74 G 01 36 41.7451236624 +15 47 01.107512304 10.52 10.00 9.46 9.16   ~ 1553 1
2 M 82 IG 09 55 52.430 +69 40 46.93 9.61 9.30 8.41     ~ 5585 6
3 NGC 4562 GiG 12 35 34.5672266616 +25 50 58.387185060   14.6       ~ 80 0
4 IC 3571 G 12 36 19.991 +26 05 01.58           ~ 22 0
5 NGC 4565 LIN 12 36 20.804 +25 59 14.61   13.61 12.43     ~ 913 0
6 3C 295 Sy2 14 11 20.467 +52 12 09.52   22.34 20.80 18.54   ~ 946 5
7 NGC 7462 GiG 23 02 46.494 -40 50 06.71   12.07   11.27 12.1 ~ 90 0

To bookmark this query, right click on this link: simbad:objects in 2019A&A...628L...3H and select 'bookmark this link' or equivalent in the popup menu


2022.05.28-10:36:25

© Université de Strasbourg/CNRS

    • Contact