Related papers: Weak Metallic Emission Lines in Early B-Type Stars

We present long-slit spectrophotometric observations in the red and near infrared of 12 HII galaxies. The spectral range includes the sulphur lines [SII] at wavelengths 6716, 6731 angstroms and [SIII] at 6312 angstroms and 9069, 9532…

Submillimeter Array 1.3mm line and continuum observations toward the young massive star-forming region IRAS18182-1433 are presented. The data are complemented with short-spacing CO(2-1) observations and SiO(1-0) data from the VLA. Multiple…

Although it is well known that massive galaxies have central black holes, most of them accreting at low Eddington ratios, many important questions still remain open. Among them, are the nature of the ionizing source, the characteristics and…

We present the detection of extremely broad, double-peaked, highly polarized Halpha emission lines in the nuclei of the well-known Seyfert 2 galaxies NGC 2110 and NGC 5252. These hidden broad Halpha emission lines, visible only in scattered…

We observe a sample of 8 evolved stars in the Galactic Bulge in the CO J = 2 - 1 line using the Submillimeter Array (SMA) with angular resolution of 1 - 4 arcseconds. These stars have been detected previously at infrared wavelengths, and…

The results from deep long-slit spectroscopy of nine edge-on spiral galaxies with known extraplanar line emission are reported. Emission from Halpha, [N II] lambda 6548, 6583, and [S II] lambda 6716, 6731 is detected out to heights of a few…

From an analysis of the spectrum (4000\AA to 8800\AA) of HD~101584 it is found that most of the neutral and single ionized metallic lines are in emission. The forbidden emission lines of [OI] 6300\AA and 6363\AA and [CI] 8727\AA are…

We have carried out a high-dispersion (R~30,000) echelle spectroscopic survey of 16 Type II supernovae (SNe) to search for narrow emission lines from circumstellar nebulae ejected by their massive progenitors. Circumstellar nebulae, if…

Irradiation effects in close binaries are crucial for a reliable determination of system parameters and understanding the close binary evolution. We study irradiated light originating from the low mass component of an eclipsing system…

We report the results of our systematic survey for Galactic 6.7 GHz Class II CH$_3$OH maser emission toward a sample of young stellar objects. The survey was conducted with the Shanghai Tianma Radio Telescope (TMRT). The sample consists of…

The $\lambda$ Boo stars are chemically peculiar A-type stars whose abundance anomalies are associated with the accretion of metal-poor material. We searched for $\lambda$ Boo stars in the southern hemisphere in a targeted spectroscopic…

I Zw 18 is the most metal poor star-forming galaxy known and is an ideal laboratory to probe stellar evolution theory at low metallicities. Using archival HST WFPC2 imaging and FOS spectroscopy we were able to improve previous studies. We…

We have obtained 40 high-resolution circular spectropolarimetric measurements of 12 slowly-pulsating B (SPB) stars, 8 Beta Cephei stars and two Be stars with the ESPaDOnS and NARVAL spectropolarimeters. The aim of these observations is to…

We present the results of optical and near-IR spectroscopic and near-IR photometric observations of the emission-line stars Hen3-298 and Hen3-303. Strong emission in the H-alpha line is found in both objects. The presence of Fe II and [O I]…

We perform local excitation calculations to obtain line opacities and emissivity ratios and compare them with observed properties of H, He I, O I, Ca II, and Na I lines to determine the density, temperature, and photon ionization rate. We…

We report interferometric measurements of [NII] 205 um fine-structure line emission from a representative sample of three galaxies at z=5-6 using the Atacama Large (sub)Millimeter Array (ALMA). These galaxies were previously detected in…

We report the serendipitous discovery of a heavily reddened Wolf-Rayet star that we name WR142b. While photometrically monitoring a cataclysmic variable, we detected weak variability in a nearby field star. Low-resolution spectroscopy…

We present new abundances derived from Cu I, Cu II, Zn I, and Zn II lines in six warm (5766 < Teff < 6427 K), metal-poor (-2.50 < [Fe/H] < -0.95) dwarf and subgiant (3.64 < log g < 4.44) stars. These abundances are derived from archival…

We present results from SMA observations of the star forming region Cepheus A-East at ~340 GHz (875 micron) with 0.7'' - 2'' resolution. At least four compact submm continuum sources have been detected, as well as a rich forest of hot core…

The physical conditions of the circumgalactic medium are probed by intervening absorption-line systems in the spectrum of background quasi-stellar objects out to the epoch of cosmic reionization. A correlation between the ionization state…