Skip to main content Accessibility help
×
Home

0.8mm extragalactic surveys of nearby galaxies

  • Ilhuiyolitzin Villicaña-Pedraza (a1), Sergio Martín (a2), Jesus Martín-Pintado (a3), Miguel Requena-Torres (a4), Rolf Guesten (a4), Jairo Armijos (a5), Juan Pablo Pérez-Beaupuits (a2), Bernd Klein (a4), Stefan Heyminck (a4), Angeles I. Díaz (a1), Luc Binette (a6), Francisco Carreto-Parra (a7) and Rebeca Aladro (a2)...

Abstract

We present the first submillimetric line survey of extragalactic sources carried out by APEX. The surveys cover the 0.8 mm atmospheric window from 270 to 370GHz toward NGC253, NGC4945 and Arp220. We found in NGC 253, 150 transitions of 26 molecules. For NGC 4945, 136 transitions of 24 molecules, and 64 transitions of 17 molecules for Arp 220. Column densities and rotation temperatures have been determinate using the Local Thermodinamical Equilibrium(LTE) line profile simulation and fitting in the MADCUBA IJ software. The differences found in ratios between the Galactic Center and the starburst galaxies NGC 4945 and NGC 253 suggest that the gas is less processed in the latter than in the Galactic Center. The high 18O/17O ratios in the galaxies NGC 4945 and NGC 253 suggest also material less processed in the nuclei of these galaxies than in the Galactic Center. This is consistent with the claim that 17O is a more representative primary product than 18O in stellar nucleosynthesis (Wilson and Rood 1994); Also, we did a Multitransitions study of H3O+ at 307GHz, 364GHz, 388GHz and 396GHz. From our non-LTE analysis of H3O+ in NGC253 with RADEX we found that the collisional excitation can not explain the observed intensity of the ortho 396 GHz line. Excitation by radiation from the dust in the Far-IR can roughly explain the observations if the H2 densities are relatively low. From the derived H3O+ column densities we conclude that the chemistry of this molecule is dominated by ionization produce by the starburst in NGC253 (UV radiation from the O stars) and Arp 220 (cosmic rays from the supernovae) and likely from the AGN in NGC4549 (X-rays ); Finally, we report, for the first time, the tentative detection of the molecular ion HCNH+ (precursor of HCN and HNC) toward a galaxy, NGC4945, abundance explain the claimed enhancement of HCN abundance in the AGN, due to the enhancement of the ionization rate by X-rays. The abundance is much larger than the Galactic center of the Milky Way.

    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      0.8mm extragalactic surveys of nearby galaxies
      Available formats
      ×

      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      0.8mm extragalactic surveys of nearby galaxies
      Available formats
      ×

      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      0.8mm extragalactic surveys of nearby galaxies
      Available formats
      ×

Copyright

MathJax
MathJax is a JavaScript display engine for mathematics. For more information see http://www.mathjax.org.

Keywords

Related content

Powered by UNSILO

0.8mm extragalactic surveys of nearby galaxies

  • Ilhuiyolitzin Villicaña-Pedraza (a1), Sergio Martín (a2), Jesus Martín-Pintado (a3), Miguel Requena-Torres (a4), Rolf Guesten (a4), Jairo Armijos (a5), Juan Pablo Pérez-Beaupuits (a2), Bernd Klein (a4), Stefan Heyminck (a4), Angeles I. Díaz (a1), Luc Binette (a6), Francisco Carreto-Parra (a7) and Rebeca Aladro (a2)...

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.