We present the final public data release of the VLT/ISAAC near-infrared imaging survey in the GOODS-South field. The survey covers an area of 172.5, 159.6 and 173.1arcmin^2^ in the J, H, and Ks bands, respectively. For point sources total limiting magnitudes of J=25.0, H=24.5, and Ks=24.4 (5{sigma}, AB) are reached within 75% of the survey area. Thus these observations are significantly deeper than the previous EIS Deep Public Survey which covers the same region. The image quality is characterized by a point spread function ranging between 0.34" and 0.65" FWHM. The images are registered to a common astrometric grid defined by the GSC 2 with an accuracy of ~0.06" RMS over the whole field. The overall photometric accuracy, including all systematic effects, adds up to 0.05mag. The data are publicly available from the ESO science archive facility.
alpha Centauri is our closest stellar neighbor, at a distance of only 1.3pc, and its two main components have spectral types comparable to the Sun. This is therefore a favorable target for an imaging search for extrasolar planets. Moreover, indications exist that the gravitational mass of alpha Cen B is higher than its modeled mass, the difference being consistent with a substellar companion of a few tens of Jupiter masses. We searched for faint comoving companions to alpha Cen B. As a secondary objective, we built a catalogue of the detected background sources. We used the NACO adaptive optics system of the VLT in the J, H, and Ks bands to search for companions to alpha Cen B. This instrument allowed us to achieve a very high sensitivity to point-like sources, with a limiting magnitude of m_Ks~18 at 7" from the star. We complemented this data set with archival coronagraphic images from the HST-ACS instrument to obtain an accurate astrometric calibration.
We investigate three embedded massive star-forming regions using the Near-Infrared Imager (NIRIM) camera on the 3.5m WIYN telescope. We report J-, H-, and K'-band photometry in the clusters AFGL437, AFGL5180, and AFGL5142, and use these results to probe the stellar populations, extinction, and ages of the clusters.
We present near-IR (NIR) J, H, and Ks images and K-band spectroscopy of two newly discovered stellar clusters at different stages of evolution. Our spectra suggest the presence of massive young stellar objects in the heavily embedded cluster in the star-forming region near radio source G353.4-0.4 and an O5-O6V star in the cluster near radio source G305+00.2.
The second largest H II region in the Large Magellanic Cloud, N11B (LHA 120-N 11B) has been surveyed in the near-IR. We present JHKs images of the N11B nebula. These images are combined with CO (1->0) emission-line data and with archival New Technology Telescope and Hubble Space Telescope WFPC2 optical images to address the star formation activity of the region. IR photometry of all the IR sources detected is given. We confirm that a second generation of stars is currently forming in the N11B region. Our IR images show the presence of several bright IR sources that appear to be located toward the molecular cloud as seen from the CO emission in the area.
We study the Large Magellanic Cloud Papillon Nebula (N 159-5), a conspicuous High Excitation Blob (HEB) lying in the star forming complex N 159. Using JHK near-infrared photometry obtained at the ESO VLT with the ISAAC camera, we examine the stellar populations associated with the Papillon, tracing their history using stellar evolution models. Two populations are revealed: one composed of young, massive stars with an age ~3Myr, and a second consisting of older lower mass stars of age spreading between 1 and 10Gyr. We analyze the properties of those populations and discuss their significance in the context of N 159. We also estimate that if the star at the center of the Papillon is single its initial mass is ~50 solar masses and it is affected by an extinction Av~7mag.
We present J, H, and Ks photometry of the Orion Nebula Cluster (ONC) obtained at the CTIO/Blanco 4m telescope at Cerro Tololo with the Infrared Side Port Imager camera. From the observations we have assembled a catalog of about ~7800 sources distributed over an area of approximately 30'x40', the largest of any survey deeper than the Two Micron All Sky Survey (2MASS) in this region. The catalog provides absolute coordinates accurate to about 0.15-arcsec and 3{sigma} photometry in the 2MASS system down to J~=19.5mag, H~=18.0mag, Ks~=18.5mag, enough to detect planetary size objects 1Myr old under A_V_~=10mag of extinction at the distance of the Orion Nebula.
We have used the Two Micron All Sky Survey and Palomar Observatory Sky Survey photographic plates, digitized by the US Naval Observatory's Precision Measuring Machine program, to derive proper motions over a 100 square degree, spatially complete region centered on the Praesepe open cluster. Proper-motion measurements spanned the magnitude range R~12-19, which covers most of the lower main sequence in Praesepe. The incidence of H{alpha} emission from moderate-resolution (~2600), red spectroscopy of 434 faint candidate members and 126 field control stars demonstrates that ~60%-80% of candidates within 2{deg} of the cluster center are genuine Praesepe members.
JHKs photometry is presented from a 3.5yr survey of the central regions of the irregular galaxy NGC 6822. The morphology of the colour-magnitude and colour-colour diagrams is discussed with particular reference to M-, S- and C-type asymptotic giant branch (AGB) stars and to M supergiants. Mean JHKs magnitudes and periods are given for 11 O-rich and 50 presumed C-rich Miras. Data are also listed for 27 large-amplitude AGB stars without periods and for 69 small-amplitude AGB variables. The slope of the bolometric period-luminosity relation for the C-rich Miras is in good agreement with that in the Large Magellanic Cloud. Distance moduli derived from the C- and O-rich Miras are in agreement with other estimates. The period distribution of C-rich Miras in NGC 6822 is similar to that in the Magellanic Clouds, but differs from that in the dwarf spheroidals in the Local Group. In the latter there is a significant proportion of large-amplitude, short-period variables indicating a population producing old carbon-rich AGB stars.
We report the discovery of a new young stellar cluster and molecular cloud located in the far outer Galaxy, seen towards IRAS 06361-0142, and we characterise their properties. Near-infrared images obtained with VLT/ISAAC through JHK filters, millimetre line observations of CO(1-0) obtained with SEST, and VLA 6cm continuum maps obtained from archive data.
