Jagiellonian University Repository

Hot gas and magnetic arms of NGC 6946 : indications for reconnection heating?

Communities & Collections

pcg.skipToMenu

Hot gas and magnetic arms of NGC 6946 : indications for reconnection heating?

Show full item record

dc.contributor.author Weżgowiec, Marek [SAP13905507] pl
dc.contributor.author Ehle, M. pl
dc.contributor.author Beck, R. pl
dc.date.accessioned 2016-01-04T10:45:13Z
dc.date.available 2016-01-04T10:45:13Z
dc.date.issued 2016 pl
dc.identifier.issn 0004-6361 pl
dc.identifier.uri http://ruj.uj.edu.pl/xmlui/handle/item/18853
dc.language eng pl
dc.rights Udzielam licencji. Uznanie autorstwa - Użycie niekomercyjne - Na tych samych warunkach 4.0 Międzynarodowa *
dc.rights.uri http://creativecommons.org/licenses/by-nc-sa/4.0/legalcode.pl *
dc.title Hot gas and magnetic arms of NGC 6946 : indications for reconnection heating? pl
dc.type JournalArticle pl
dc.description.additional Reproduced with permission from Astronomy & Astrophysics, © ESO pl
dc.abstract.en Context. The grand-design face-on spiral galaxy NGC 6946 is remarkable because of its high star formation activity, the massive northern spiral arm, and the magnetic arms, which are observed in polarized radio synchrotron emission and are located between the optical arms and possibly are magnetic reconnection regions. Aims. We used electron densities and temperatures in star-forming (active) and less active regions and compared them to findings from the analysis of the radio data to study the energy budget of NGC 6946. The hot gas above the magnetic arms between the optical arms might suggest gas heating by reconnection. We also study the population of point sources in NGC 6946, including the origin of the puzzling ultra-luminous emission complex MF16. Methods. X-ray observations of NGC 6946 performed with XMM-Newton were used to study the emission from X-ray point sources and diffuse hot gas, including the magnetic arms and the halo. Spectral fitting of the diffuse X-ray emission allowed us to derive temperatures of the hot gas. With assumptions about the emission volume, this allowed us to estimate gas densities, masses, and cooling times. Results. To explain the X-ray emission from the spiral arms of NGC 6946 two-temperature plasma models are needed to account for the disk and halo emission. The interarm regions show only one thermal component. We observe that the temperature of the hot gas in and above the magnetic arm regions increases slightly when compared to the average temperatures in the areas in and above the spiral arms. For the southwestern part of the disk, which is depolarized in the radio range by Faraday rotation, we find more efficient mixing of disk and halo gas. Conclusions. We propose magnetic reconnection in the magnetic arm regions of NGC 6946 as the possible cause of the additional heating of the gas and ordering of the magnetic fields. In the southwestern part of the galactic disk we observed indications of a possible faster outflow of the hot gas. A very hot gas within the MF 16 nebula possibly suggests shock heating by a supernova explosion. pl
dc.subject.en galaxies: individual: NGC 6946 pl
dc.subject.en galaxies: ISM pl
dc.subject.en galaxies: spiral pl
dc.subject.en galaxies: magnetic fields pl
dc.description.volume 585 pl
dc.identifier.doi 10.1051/0004-6361/201526833 pl
dc.identifier.eissn 1432-0746 pl
dc.title.journal Astronomy & Astrophysics pl
dc.language.container eng pl
dc.affiliation Wydział Fizyki, Astronomii i Informatyki Stosowanej : Instytut – Obserwatorium Astronomiczne pl
dc.subtype Article pl
dc.identifier.articleid A3 pl
dc.rights.original OTHER; otwarte czasopismo; ostateczna wersja wydawcy; po opublikowaniu; 12 pl
dc.identifier.project ROD UJ / P pl
.pointsMNiSW [2016 A]: 35


Files in this item

Name: wezgowiec_ehle_be ...
Size: 6.534Mb
Format: PDF
View/Open
Icon
Name: wezgowiec_ehle_be ...
Size: 6.534Mb
Format: OpenOffice Writer
View/Open
Icon
Name: wezgowiec_ehle_be ...
Size: 79.01Kb
Format: Text file
View/Open

This item appears in the following Collection(s)

Udzielam licencji. Uznanie autorstwa - Użycie niekomercyjne - Na tych samych warunkach 4.0 Międzynarodowa Except where otherwise noted, this item's license is described as Udzielam licencji. Uznanie autorstwa - Użycie niekomercyjne - Na tych samych warunkach 4.0 Międzynarodowa