Related papers: Through the fog: a complementary optical galaxy cl…
Dust has long been identified as a barrier to measuring inherent galaxy properties. However, the link between dust and attenuation is not straightforward and depends on both the amount of dust and its distribution. Herschel imaging of…
We describe the use of partially overlapping galaxies to provide direct measurements of the effective absorption in galaxy disks, independent of assumptions about internal disk structure. The non-overlapping parts of the galaxies and…
Among star forming galaxies, a spectral combination of a strong Hdelta line in absorption and a moderate [OII] emission has been suggested to be a useful method to identify dusty starburst galaxies at any redshift, on the basis of optical…
Optical emission lines are used to categorize galaxies into three groups according to their dominant central radiation source: active galactic nuclei, star formation, or low-ionization (nuclear) emission regions [LI(N)ERs] that may trace…
We present new quantitative classification methods for emission-line galaxies, which are specially designed to be used in deep galaxy redshift surveys. A good segregation between starbursts and active galactic nuclei, i.e. Seyferts 2s and…
We present a method to study the photometric properties of galaxies in filaments by stacking the galaxy populations between pairs of galaxy clusters. Using Sloan Digital Sky Survey data, this method can detect the inter-cluster filament…
We examine the evolutionary status of luminous, star-forming galaxies in intermediate-redshift clusters by considering their star formation rates and the chemical and ionsiation properties of their interstellar emitting gas. Our sample…
We compare properties of galaxies in loose groups with those in field environment by analyzing the Nearby Optical Galaxy (NOG) catalog of galaxy systems. We consider as group galaxies, objects belonging to systems with at least five members…
The UV spectra of Galactic and extragalactic sightlines often show OVI absorption lines at a range of redshifts, and from a variety of sources from the Galactic circumgalactic medium to AGN outflows. Inner shell OVI absorption is also…
We derive oxygen abundances for a sample of 40 luminous (M_{B} < -19), star-forming, mostly disk, field galaxies with redshifts in the range 0.2 < z < 0.8$, with a median of <z> = 0.45. Oxygen abundances, relative to hydrogen, of the…
We explore the kinematics of ionized gas via the [O III] $\lambda$5007 emission lines in active galactic nuclei (AGN) selected on the basis of their mid-infrared (IR) emission, and split into obscured and unobscured populations based on…
There has been great progress in recent years in discovering star forming galaxies at high redshifts (z>5), close to the epoch of reionization of the intergalactic medium (IGM). The WFC3 and ACS cameras on the Hubble Space Telescope have…
JWST spectra revealing Lyman-$\alpha$ (Ly$\alpha$) absorption in $z\sim 5-14$ galaxies offer a unique probe of reionization's earliest stages. However, disentangling absorption by the increasingly neutral intergalactic medium (IGM) from…
Potential contamination from low/intermediate-redshift galaxies, such as objects with a prominent Balmer break, affects the photometric selection of high-redshift galaxies through identification of a Lyman break. Traditionally,…
The presence of evolved stars in high-redshift galaxies can place valuable indirect constraints on the onset of star formation in the Universe. Thus we use PEARLS GTO and public NIRCam photometric data to search for Balmer-break candidate…
We have successfully constructed a catalog of HI-rich galaxies selected from the Minnesota Automated Plate Scanner Catalog of the Palomar Observatory Sky Survey (POSS I) based solely on optical criteria. We identify HI-rich candidates by…
Galaxies uncovered in the Zone of Avoidance (ZOA) with deep optical searches are compared to the distribution of objects in the 2MASS Extended Source Catalog (2MASX). While the galaxy density of optical surveys is strongly correlated to the…
We present the gas-phase oxygen abundance (O/H) for a sample of 131 star-forming galaxies at intermediate redshifts ($0.2<z<1.0$). The sample selection, the spectroscopic observations (mainly with VLT/FORS) and associated data reduction,…
We present Keck/MOSFIRE spectra of the diagnostic nebular emission lines [OIII]5007,4959, [OII]3727, and H-beta for a sample of 15 redshift z=3.1-3.7 Ly-alpha emitters (LAEs) and Lyman break galaxies (LBGs). In conjunction with spectra from…
Rest-frame UV spectral lines of star-forming galaxies are systematically offset from the galaxies' systemic redshifts, probably because of large-scale outflows. We calibrate galaxy redshifts measured from rest-frame UV lines by utilizing…