Bibcode
Leaman, R.; Erroz-Ferrer, S.; Cisternas, M.; Knapen, J. H.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 450, Issue 3, p.2473-2485
Advertised on:
7
2015
Citations
5
Refereed citations
4
Description
Using multiwavelength kinematic and photometric data we have analysed
the gaseous and stellar properties of a previously uncharacterized
low-mass star-forming companion and newly discovered stellar stream seen
projected against the edge-on spiral galaxy NGC 7241. The companion
object was identified serendipitously as an offset velocity component in
H α Fabry-Perot observations along the line of sight to NGC 7241,
and is most prominent visually in UV and blue wavelengths. Its occulting
position with respect to NGC 7241 allows measurement of its dust
extinction properties which are then combined with photometric spectral
energy distribution fitting and long-slit spectroscopy to study star
formation (SF) in this gas-rich accreting dwarf galaxy. The dynamical
properties of the stream and companion suggest that they may likely be
remnants of the same low-mass progenitor dwarf galaxy which is being
disrupted during its accretion on to NGC 7241 - with the companion's
recent SF triggered during its passage with the disc of NGC 7241. This
is supported by the companion's metallicity and SF rates, the asymmetric
SF in the disc of NGC 7241, as well as the coincident velocity of the
extraplanar H I filament and the star-forming companion. In contrast,
mass estimates from dynamical modelling of NGC 7241 rule out an
interaction between NGC 7241 and UGC 11964 (the other large spiral
galaxy in the group) within the last ˜3 Gyr - making such an
interaction a poor candidate for inducing the recent SF in the system.
Together, the data for this system offer a window into how SF proceeds
in low-mass mergers.
Related projects
Spiral Galaxies: Evolution and Consequences
Our small group is well known and respected internationally for our innovative and important work on various aspects of the structure and evolution of nearby spiral galaxies. We primarily use observations at various wavelengths, exploiting synergies that allow us to answer the most pertinent questions relating to what the main properties of
Johan Hendrik
Knapen Koelstra