Related papers: Massive stars as important contributors to two mic…
High-quality K-band spectra of point sources, deeply embedded in massive star-forming regions, have revealed a population of 20 young massive stars showing no photospheric absorption lines, but only emission lines. The K-band spectra…
Broadband continuum images of the edge-on galaxy NGC 891 at 850 and 450 microns are presented. These images are qualitatively very similar to the 1300 micron and CO images obtained by others. With respect to the 850 micron continuum, CO is…
We present a detailed study of SMM 02399-0136, a hyperluminous, active galaxy selected from a sub-mm survey of the distant Universe. This galaxy is the brightest source in the fields of seven rich, lensing clusters - total area 0.01 deg^2 -…
Observations for seven infrared luminous starburst galaxies are reported in the mid-infrared from 8 - 18 microns using the Keck Telescopes with spatial resolution approaching the diffraction limit. All of the galaxies observed show evidence…
This article presents high-resolution interferometric mosaics in the 850 micron waveband of two massive, quiescent infrared dark clouds. The two clouds were chosen based on their likelihood to represent environments preceding the formation…
The correlation, found in nearby galaxies, between black hole mass and stellar bulge mass implies that the formation of these two components must be related. Here we report submillimeter photometry of eight x--ray absorbed active galactic…
The brightest galaxy in the nearby Perseus cluster, NGC1275, is surrounded by a network of filaments. These were first observed through their Halpha emission but are now known to have a large molecular component with a total mass…
We report the detection of CO(3-2) emission from the submillimeter-selected hyperluminous galaxy SMM 02399-0136. This galaxy is the brightest source detected in the recent SCUBA surveys of the submillimeter sky. The optical counterpart of…
Stars with masses in the range from about 1.3 to 3.5 Mo pass through an evolutionary stage where they become carbon stars. In this stage, which lasts a few Myr, these stars are extremely luminous pulsating giants. They are so luminous in…
We have measured the strengths of Ca II Triplet and Mgb stellar absorption lines in the nuclear and off-nuclear spectra of Seyfert galaxies. These features are diluted to varying degrees by continuum emission from the active nucleus and…
Through the study of two absorption spectral features in the optical range (Mg2 and the 4000 A break), we find evidence for star formation in the inner regions of cooling-flow galaxies. The application of simple stellar population models…
Mergers in the local universe present a unique opportunity for studying the transformations of galaxies in detail. Presented here are recent results, based on multi-wavelength, high-resolution imaging and medium resolution spectroscopy,…
We have obtained mid-infrared spectra of nine cool-core galaxy clusters with the Infrared Spectrograph aboard the Spitzer Space Telescope. X-ray, ultraviolet and optical observations have demonstrated that each of these clusters hosts a…
Quiescent galaxies with little or no ongoing star formation dominate the galaxy population above $M_{*}\sim 2 \times 10^{10}~M_{\odot}$, where their numbers have increased by a factor of $\sim25$ since $z\sim2$. Once star formation is…
We present new observations of the famous starburst galaxy NGC 5253 which owes its celebrity to possibly being the youngest and closest starburst galaxy known. Our observations in the infrared and millimeter contribute to shed light on the…
The mid infrared spectra of the starbursts show the 9.7$\mu m$ silicate absorption feature and strong mid infrared emission bands centered at 6.2, 7.7, and 11.3 $\mu$m. Illustrative models of the {\it active} galaxies are presented: As the…
We have obtained V and I-band photometry for about 17500 stars in the field of the dwarf irregular galaxy NGC3109, located in the outskirts of the Local Group. The photometry allows us to study the stellar populations present inside and…
We have tested some relations for star formation rates used in extra-galactic studies for regions within the Galaxy. In nearby molecular clouds, where the IMF is not fully-sampled, the dust emission at 24 micron greatly underestimates star…
To study large-scale structure in the Universe a full census of the contents are required. This is even more important when the processes of galaxy formation are being investigated. In the last year the population of distant galaxies that…
Young massive stars and stellar clusters continuously form in the Galactic disk, generating new HII regions within their natal giant molecular clouds and subsequently enriching the interstellar medium via their winds and supernovae. Massive…