My Python library

Here is the dropbox link to my ever growing and evolving little library of Python routines (Python 3 compatible).

• Collection of miscellaneous little helper routines, including a table crossmatching an cone-searching routine
• Imaging-related routines, e.g., finding point sources, simulate observations, create multiplot galleries
• my custom VISIR pipeline
• some WISE related routines, e.g., for converting the magnitudes into flux densities

Most of the routines are documented and should be self-explanatory but I am still working on a more detailed documentation, version control/history and so on. Please let me know if you have any questions!

TORUS2018_dasmus by Daniel Asmus on Scribd

Resolving the dust structure in active galactic nuclei

Colloquium talk given at the Observatory of Belgrade in 2017 as an overview of high angular resolution imaging of AGN

The nuclei of many galaxies shine bright throughout all the electromagnetic spectrum. This powerful emission if often brighter than all the star light of the galaxy combined. Its source is an accreting supermassive black hole in the galaxy center. However, around half of the accretion disk emission does not escape the nuclear region but is instead absorbed by an unknown dust structure and reemitted in the infrared. I will present an overview of our attempts to detect and resolve this dust structure in nearby active galactic nuclei (AGN) and review the surprising results emerging from recent highest angular resolution observations.

Resolving the dust structure in active galactic nuclei by Daniel Asmus on Scribd

The predominance of infrared emission from the polar region of accreting supermassive black holes

Talk given at the AGN conference Garching 2016...

The predominance of infrared emission from the polar region of accreting supermassive black holes

Finally published: The subarcsecond mid-infrared view of local active galactic nuclei: I. The N- and Q-band imaging atlas

The AGN mid-infrared atlas is finally published!

The full paper including the appendix with all the object descriptions is available on arXiv: http://arxiv.org/abs/1310.2770.

ADS: http://adsabs.harvard.edu/abs/2014MNRAS.439.1648A

The tables can be accessed through CDS: http://cdsarc.u-strasbg.fr/cgi-bin/VizieR?-source=J/MNRAS/439/1648.

The images, fits files, tables and object descriptions can be accessed through the Virtual Observatory  via GAVO (Topcat, Aladin etc.; ID: sasmirala). Original front-end: http://dc.g-vo.org/sasmirala.

Direct download of collections:

• PDF with all object descriptions (Appendix only):  http://mnras.oxfordjournals.org/content/suppl/2014/02/17/stu041.DC1/AGN_atlas_MIR_paper_onlineonly.pdf
• All fits files: http://dc.zah.uni-heidelberg.de/sasmirala/q/prod/static/collection/fits.tar.gz
• All tables: http://dc.zah.uni-heidelberg.de/sasmirala/q/prod/static/collection/tables.tar.gz
• All plots: http://dc.zah.uni-heidelberg.de/sasmirala/q/prod/static/collection/plots.tar.gz

Please contact me in case of questions or comments! I am happy to give support to anyone who wants to use the data!

The subarcsecond mid-infrared view of local active galactic nuclei: I. The N- and Q-band imaging atlas

Abstract:

We present the first subarcsecond-resolution mid-infrared (MIR) atlas of local active galactic nuclei (AGN) containing 253 objects with a median redshift of z = 0.016. It comprises all available MIR imaging observations performed to date with ground-based 8-meter class telescopes and includes in total 895 independent photometric measurements, of which more than 60% are previously unpublished.We detect extended nuclear emission in at least 21% of the objects, while another 19% appear clearly point-like, and the remaining objects cannot be constrained. Subarcsecond resolution allows us to isolate the emission of the AGN on scales of a few tens of parsecs for the bulk of the sample and obtain nuclear photometry in multiple filters for the objects. The photometry is used to construct median spectral energy distributions (SEDs) for the different optical AGN types and estimate the individual MIR 12 and 18 um continuum luminosities, which range over more than six orders of magnitude. We also analyse the arcsecond-scale MIR emission as probed by Spitzer and compare it to the subarcsecond-scale emission. The continuum emission is on average 20% lower on subarcsecond scales with a large scatter that depends mostly on the object distance or luminosity. The silicate feature strength is similar on both scales and generally appears in emission (absorption) in type I (II) AGN. However, the PAH emission appears weaker or absent on subarcsecond scales, indicating that most of the star formation has been resolved out. The differences of the MIR SEDs on both scales are particularly large for AGN/starburst composites and close-by (and weak) AGN. Because of its size and characteristics, the AGN MIR atlas is well-suited not only for detailed investigation of individual sources but also for sample studies of AGN unification.

This is the submission version of the mid-infrared atlas paper (451 pages, 930 Figures, ~50MB, submitted to MNRAS).

Download: https://www.dropbox.com/s/njug032m3wfsimr/AGN_atlas_MIR_paper_subm.pdf

Comments are welcome!

For the preliminary data tables in CDS format, see https://www.dropbox.com/s/u36i0xjimfhojst/tables.tar.gz .

The final tables and fits images will be available via the German VO (GAVO) and CDS after acceptance.


This is the poster of the IAU Symposium S304: Multiwavelength AGN Surveys and Studies in Armenia (Oct 2013):

The sharpest view of the local AGN population at mid-infrared and X-ray wavelengths

Talk and proceedings of the Torus Workshop 2012 held at the University of Texas at San Antonio, 5-7 December 2012

The proceeding contribution can be found here.

The mid-infrared properties of local active galactic nuclei at high-angular resolution by Daniel Asmus