ESO Messenger 155, (2014), 29-32 The VISTA Variables in the V\'ia L\'actea (VVV) survey is one of six public
ESO surveys, and is now in its 4th year of observing. Although far from being
complete, ...the VVV survey has already delivered many results, some directly
connected to the intended science goals (detection of variables stars,
microlensing events, new star clusters), others concerning more exotic objects,
e.g. novae. Now, at the end of the fourth observing period, and comprising
roughly 50% of the proposed observations, the actual status of the survey, as
well some of the results based on the VVV data, are presented.
Using high spatial resolution Hubble Space Telescope/Advanced Camera for Surveys archival imaging observations of Arp 116, centred on the elliptical galaxy NGC 4649, we explore the novel technique of ...pixel-by-pixel analysis of the galaxy's colour-magnitude diagramme to search for any evidence of recent enhanced star formation due to the apparent tidal interaction with its spiral companion, NGC 4647. From a detailed analysis of the system's geometry, and based on additional circumstantial evidence from extant multi-wavelength observations, we conclude that, while there may be grounds for the tidal-interaction assumption for this system, any interaction has thus far been of insufficient strength to trigger an enhanced level of recent star formation in the elliptical component, although close inspection of our colour images shows a faint excess of bluer pixels (a ~0.20 mag bluer "loop") in the elliptical galaxy on the side of the spiral companion. Given that there appears to be a moderate reservoir of available gas for ongoing star formation (although at low column density), this suggests that we are currently witnessing the onset of the tidal interaction between NGC 4647 and NGC 4649. In addition, the triggering of new star formation in NGC 4649 may be significantly impeded due to the much lower mass of the spiral component.
VISTA Variables in the V\'ıa Láctea (VVV) is one of the six ESO Public Surveys operating on the new 4-meter Visible and Infrared Survey Telescope for Astronomy (VISTA). VVV is scanning the Milky Way ...bulge and an adjacent section of the disk, where star formation activity is high. One of the principal goals of the VVV Survey is to find new star clusters of different ages. In order to trace the early epochs of star cluster formation we concentrated our search in the directions to those of known star formation regions, masers, radio, and infrared sources. The disk area covered by VVV was visually inspected using the pipeline processed and calibrated \(K_{\rm S}\)-band tile images for stellar overdensities. Subsequently, we examined the composite \(JHK_{\rm S}\) and \(ZJK_{\rm S}\) color images of each candidate. PSF photometry of \(15\times15\) arcmin fields centered on the candidates was then performed on the Cambridge Astronomy Survey Unit reduced images. After statistical field-star decontamination, color-magnitude and color-color diagrams were constructed and analyzed. We report the discovery of 96 new infrared open clusters and stellar groups. Most of the new cluster candidates are faint and compact (with small angular sizes), highly reddened, and younger than 5\,Myr. For relatively well populated cluster candidates we derived their fundamental parameters such as reddening, distance, and age by fitting the solar-metallicity Padova isochrones to the color-magnitude diagrams.
The VISTA Variables in the Vía Láctea (VVV) survey is one of six public ESO surveys, and is now in its 4th year of observing. Although far from being complete, the VVV survey has already delivered ...many results, some directly connected to the intended science goals (detection of variables stars, microlensing events, new star clusters), others concerning more exotic objects, e.g. novae. Now, at the end of the fourth observing period, and comprising roughly 50% of the proposed observations, the actual status of the survey, as well some of the results based on the VVV data, are presented.
New Astron.Rev. 50 (2006) 422-425 We have been undertaking a programme on the Gemini 8-m telescopes to
demonstrate the power of integral field spectroscopy, using the optical GMOS
spectrograph, and ...the new CIRPASS instrument in the near-infrared. Here we
present some preliminary results from 3D spectroscopy of extra-galactic
objects, mapping the emission lines in a 3CR radio galaxy and in a
gravitationally lensed arc, exploring dark matter sub-structure through
observations of an Einstein Cross gravitational lens, and the star formation
time-scales of young massive clusters in the starburst galaxy NGC 1140.
We have been undertaking a programme on the Gemini 8-m telescopes to demonstrate the power of integral field spectroscopy, using the optical GMOS spectrograph, and the new CIRPASS instrument in the ...near-infrared. Here we present some preliminary results from 3D spectroscopy of extra-galactic objects, mapping the emission lines in a 3CR radio galaxy and in a gravitationally lensed arc, exploring dark matter sub-structure through observations of an Einstein Cross gravitational lens, and the star formation time-scales of young massive clusters in the starburst galaxy NGC 1140.
