1 / 27

Galactic wind in the bulge of the Andromeda galaxy

Galactic wind in the bulge of the Andromeda galaxy. Ákos Bogdán Marat Gilfanov. 23 February 2009. Origin of X-ray emission from galaxies. AGNs X-ray binaries Faint compact sources Hot ionized gas Cosmic X-ray Background. Ákos Bogdán. Kunming 2009. Origin of X-ray emission from galaxies.

zuriel
Download Presentation

Galactic wind in the bulge of the Andromeda galaxy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Galactic wind in the bulge of the Andromeda galaxy Ákos Bogdán Marat Gilfanov 23 February 2009

  2. Origin of X-ray emission from galaxies • AGNs • X-ray binaries • Faint compact sources • Hot ionized gas • Cosmic X-ray Background Ákos Bogdán Kunming 2009

  3. Origin of X-ray emission from galaxies X-ray binaries • Accreting black holes and neutron stars • Luminosity: 1035-1039 erg/s • Resolved at thedistance of M31 Ákos Bogdán Kunming 2009

  4. Origin of X-ray emission from galaxies Faint compact sources • Cataclysmic variables • Active binaries • Luminosity: • 1027-1034 erg/s • ~ to stellar mass • Galactic ridge X-ray emission Gilfanov 2004 Revnivtsev et al. 2006 Sazonov et al. 2006 Ákos Bogdán Kunming 2009

  5. Origin of X-ray emission from galaxies Hot ionized gas • Sub-keV temperature • NGC 1316: • Elliptical galaxy • Mass of ISM: 109 M⊙ • M32: • Dwarf galaxy • X-ray light ~ K-band light • No gas detected Revnivtsev et al. 2007 Kim & Fabbiano 2003 Ákos Bogdán Kunming 2009

  6. M31 • 780 kpc • Spiral galaxy • i=77° Ákos Bogdán

  7. X-ray data • Chandra • ~240 ks exposure time • 0.5” (1.9 pc) angular resolution • XMM-Newton • ~640 ks exposure time • Larger effective area • Better coverage of M31 Ákos Bogdán Kunming 2009

  8. Ákos Bogdán Kunming 2009

  9. Unresolved X-ray emission Distribution along the major axis I. 0.5 – 2 keV Chandra –XMM-Newton –3.6 micron Ákos Bogdán Kunming 2009

  10. Unresolved X-ray emission Distribution along the major axis II. 2 – 7 keV Chandra center –Chandra south –3.6 micron Ákos Bogdán Kunming 2009

  11. Unresolved X-ray emission Distribution along the minor axis 0.5 – 1.2 keV Chandra –XMM-Newton –Spitzer Ákos Bogdán Kunming 2009

  12. Unresolved X-ray emission Shadows of spiral arms • i=77° • Western side is closer to us Ákos Bogdán Kunming 2009

  13. Unresolved X-ray emission Spectral regions Central region Outer bulge region Disk region M32 Ákos Bogdán Kunming 2009

  14. Unresolved X-ray emission Spectral analysis • Above 1.2 keV • Good agreement • Can be fitted by powerlaw • Below 1.2 keV • Soft excess component • Varying strength • Complex spectrum Ákos Bogdán Kunming 2009

  15. Unresolved X-ray emission X-ray emitting components from M31 • Broad band component • Large number of faint compact X-ray sources • Agreement between X-ray and NIR profiles • LX/LK ratios are consistent with Milky Way and M32 • Normalized spectra are consistent with each other • Soft emission in the central regions • Concentrated towards the center • Hot ionized gas • ~2.5 kpc vertical extent • Emission from star forming regions Ákos Bogdán Ákos Bogdán Kunming 2009

  16. Hot ISM Hot gas distribution • DSS optical image • Spitzer image • Chandra data Ákos Bogdán

  17. Hot ISM Why is it gas? • Does not follow near-infrared stellar light • No significant color gradients in M31 bulge • No significant young star population Ákos Bogdán Kunming 2009

  18. Hot ISM Physical properties of the gas • kT ~ 0.3 keV • LX ~ 2 ∙ 1038 erg/s • Lbol ~ 4 ∙ 1038 erg/s • Mass ~ 2 ∙ 106 Msun • Cooling time: ~ 250 million years Ákos Bogdán Kunming 2009

  19. Hot ISM Mass budget of the outflow • Stellar winds from evolved stars: ~0.0021 LK/LK,sun Msun Gyr-1 • LK ≈ 2.8 ∙ 1010 LK,sun • Mass loss rate ≈ 0.06 Msun/yr • Mass of the gas: ~ 2 ∙ 106 Msun • Replenished in ~ 35 million years < cooling time Ákos Bogdán Kunming 2009

  20. Hot ISM Energy budget of the outflow • Type Ia supernova explosions:~0.035 SN/1010LK,sun/100yr • ESNIa = 1051 erg • Energy from SN Ia: ~3 ∙ 1040 erg/s • Lift and heat the gas: ~8 ∙ 1039 erg/s • Type Ia SN are able drive a galactic wind Ákos Bogdán Kunming 2009

  21. Hot ISM Chemichal abundances • SN Ia add iron-peak elements (Fe, Ni) • High expected abundance • High resolution spectra are needed Ákos Bogdán Kunming 2009

  22. Hot ISM Current work • XMM-Newton RGS • Detailed study of abundances O VIII Fe XVII N VII O VII Spectral intensity Wavelength (Å) Ákos Bogdán Kunming 2009

  23. Conclusion • Bulk of unresolved emission originates from faint stellar type X-ray sources • Hot gas with 0.3 keV temperature • Asymmetric distribution • SN Ia driven outflow • High resolution spectra Further information: Bogdán & Gilfanov 2008, MNRAS Ákos Bogdán Kunming 2009

  24. The End

  25. Distribution along the minor axis II. 0.5 – 1.2 keV Chandra –XMM-Newton –K-band –Spitzer Ákos Bogdán Kunming 2009

  26. Other properties of the outflow Speed of the outflow vwind~ 60 km/s vsound ~ 200 km/s Sub-sonic speed Rotation? Magnetic field? Abundances SN Ia add iron-peak elements (Fe, Ni) High expected abundance Ákos Bogdán Kunming 2009

More Related