J/A+A/623/A173 SNe/SNRs in starburst galaxy Arp 220 (Varenius+, 2019)
The population of SNe/SNRs in the starburst galaxy Arp 220.
A self-consistent analysis of 20 years of VLBI monitoring.
Varenius E., Conway J.E., Batejat F., Marti-Vidal I., Perez-Torres M.A.,
Aalto S., Alberdi A., Lonsdale C.J., Diamond P.
<Astron. Astrophys. 623, A173 (2019)>
=2019A&A...623A.173V 2019A&A...623A.173V (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Galaxies, IR ; Supernovae
Keywords: galaxies: star formation - galaxies: starburst -
galaxies: individual: Arp 220 - ISM: supernova remnants -
supernovae: general
Abstract:
The nearby ultra-luminous infrared galaxy (ULIRG) Arp 220 is an
excellent laboratory for studies of extreme astrophysical
environments. For 20 years, Very Long Baseline Interferometry (VLBI)
has been used to monitor a population of compact sources thought to be
supernovae (SNe), supernova remnants (SNRs) and possibly active
galactic nuclei (AGNs). SNe and SNRs are thought to be the sites of
relativistic particle acceleration powering the star formation induced
radio emission, and are hence important for studies of e.g. the origin
of the FIR-radio correlation.
In this work we aim for a self-consistent analysis of a large
collection of Arp 220 continuum VLBI data sets. With more data and
improved consistency in calibration and imaging, we aim to detect more
sources and improve source classifications with respect to previous
studies. Furthermore, we aim to increase the number of sources with
robust size estimates, to analyse the compact source luminosity
function (LF), and to search for a luminosity-diameter (LD) relation
within Arp 220.
Using new and archival VLBI data spanning 20 years, we obtain 23
high-resolution radio images of Arp 220 at wavelengths from 18cm to
2cm. From model-fitting to the images we obtain estimates of flux
densities and sizes of all detected sources. The sources are
classified in groups according to their observed lightcurves, spectra
and sizes. We fit a multi-frequency supernova lightcurve model to the
object brightest at 6cm to estimate explosion properties for this
object.
Description:
The folder contains scripts, images, and data associated with the
paper.
The material is split in directories with README file.
Overview:
calibration - ParselTongue scripts used to calibrate archival
UVFITS data to obtain FITS images.
fitsimages - The FITS images obtained for all epochs analysed in the paper.
stacking - Script to stack FITS images from multiple epochs, and the
resulting stacked FITS images.
fitting - Scripts used to fit spherical shell models to sources
in the FITS images for all epochs.
fitresults - ASCII files with the resulting values for position,
flux density and diameter for all source fits.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
catalog.dat 113 97 Compact continuum sources detected in Arp 220
table2.dat 42 97 List of the 97 sources analysed in this work
list.dat 100 46 List of fits images
fitsimages/* . 47 Individual fits images obtained for all epochs
analysed in the paper
calibration/* . 24 ParselTongue scripts used to calibrate archival
UVFITS data to obtain FITS images
fitresults/* . 47 ASCII files with the resulting values for
position, flux density and diameter for
all source fits
fitting/* . 5 Scripts used to fit spherical shell models to
sources in the FITS images for all epochs
stacking/* . 8 Script to stack FITS images from multiple
epochs, and the resulting stacked FITS images
--------------------------------------------------------------------------------
See also:
J/ApJ/641/763 : UBVI photometry for Arp 220 star clusters (Wilson+, 2006)
J/A+A/493/481 : Maps of Arp 220 (Aalto+, 2009)
J/ApJ/799/10 : Arp 220 6 and 33GHz images (Barcos-Munoz+, 2015)
J/A+A/590/A25 : Arp 220 HCN and HCO+ data cubes (Martin+, 2016)
J/A+A/593/A86 : Arp 220 LOFAR radio images at 150MHz (Varenius+, 2016)
Byte-by-byte Description of file: catalog.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name Galaxy name (oRA+oDE, from table2.dat)
14- 37 F24.20 deg RAdeg Right ascension (J2000)
39- 61 F23.20 deg DEdeg Declination (J2000)
63- 84 F22.20 deg Size Stacked size
86-107 F22.20 Jy Flux Stacked flux
109-113 A5 --- DetBands Detected in stacked bands
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 F6.4 s oRA Offset in right ascension from
RA=15:34:57, DE=+23:30:11 (J2000)
8- 12 F5.3 s oDE Offset in declination from
RA=15:34:57, DE=+23:30:11 (J2000)
14- 16 A3 --- LName Legacy name
18- 22 A5 --- Class Class
24 A1 --- l_F6cm Limit flag on F6cm
25- 28 I4 uJy F6cm Flux density at 6cm measured by fitting a
spherical shell to BB335B
30- 32 I3 uJy e_F6cm ? rms uncertainty on F6cm
34- 37 F4.2 mas Diam ?=- Average diameter (1)
39- 42 F4.2 mas e_Diam ? rms uncertainty on average diameter
--------------------------------------------------------------------------------
Note (1): Average diameters calculated according to Sect. 2.4 from the 3.6cm
and 6cm measurements in experiments BB335A and BB335B.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 23 I4 --- Nx [8192] Number of pixels along X-axis
25- 28 I4 --- Ny [8192] Number of pixels along Y-axis
30- 39 A10 "date" Obs.date Observation date
41- 48 F8.5 GHz Freq Observed frequency
50- 55 I6 Kibyte size Size of FITS file
57- 80 A24 --- FileName Name of FITS file, in subdirectory fitsimages
82-100 A19 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Acknowledgements:
Eskil Varenius, varenius(at)chalmers.se
(End) Patricia Vannier [CDS] 13-Feb-2019