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The recently initiated Arecibo Legacy Fast ALFA (ALFALFA) survey aims to map 7000 square degrees of the high galactic latitude sky visible from Arecibo, providing a HI line spectral database covering the redshift range between -1600 km/s…

Astrophysics · Physics 2008-11-26 Riccardo Giovanelli , Martha P. Haynes , Brian R. Kent

Almost all massive stars are part of a binary system. Given the wide range of separations at which these companions are found, several observational techniques have been adopted to characterize them, but contrasts greater than 4 in the…

Solar and Stellar Astrophysics · Physics 2022-04-27 M. Reggiani , A. Rainot , H. Sana , L. A. Almeida , S. Caballero-Nieves , K. Kratter , S. Lacour , J. -B. LeBouquin , H. Zinnecker

Astrophysical masers are widely used in star formation studies. In particular, they are valuable in investigations of high-mass star-forming regions that are difficult to observe at optical frequencies. We used multi-transition data to…

Solar and Stellar Astrophysics · Physics 2025-03-17 A. Kobak , A. Bartkiewicz , K. L. J. Rygl , A. M. S. Richards , M. Szymczak , P. Wolak

The study of the multiplicity of massive stars gives hints on their formation processes and their evolutionary paths, which are still not fully understood. Large separation binaries (>50 milliseconds of arc, mas) can be probed by…

We present results from VLBI observations of continuum and OH line emission in IRAS 02524+2046 and also arcsecond-scale radio properties of this galaxy using VLA archive data. We found that there is no significant detection of radio…

Astrophysics of Galaxies · Physics 2020-07-01 Hao Peng , Zhongzu Wu , Bo Zhang , Yongjun Chen , Xingwu Zheng , Dongrong Jiang , Zhiqiang Shen , Xi Chen , Sotnikova , Yu. V

We present mid-infrared observations for a sample of 16 O-type stars. The data were acquired with the NASA Spitzer Space Telescope, using the IRS instrument at moderate resolution (R $\sim$ 600), covering the range $\sim 10-37$ microns. Our…

Solar and Stellar Astrophysics · Physics 2017-07-26 Wagner L. F. Marcolino , Jean-Claude Bouret , Thierry Lanz , Donavan S. Maia , Marc Audard

We consider the capabilities for detecting low order CO emission lines from high-z galaxies using the next generation of radio telescopes operating at 22 and 43 GHz. We employ models for the evolution of dusty star forming galaxies based on…

Astrophysics · Physics 2009-11-07 C. L. Carilli , A. W. Blain

Aims: Accurate distances to evolved stars with high mass loss rates are needed for studies of many of their fundamental properties. However, as these stars are heavily obscured and variable, optical and infrared astrometry is unable to…

Astrophysics · Physics 2009-11-13 W. H. T. Vlemmings , H. J. van Langevelde

Context: The Red MSX Source (RMS) survey has identified a large sample of candidate massive young stellar objects (MYSOs) and ultra compact (UC) HII regions from a sample of ~2000 MSX and 2MASS colour selected sources. Aims: To search for…

We present first results of the study of a set of exceptional HI sources identified in the 40% ALFALFA extragalactic HI survey catalog alpha.40 as being both HI massive (M_HI > 10^10 Msun) and having high gas fractions for their stellar…

Recent observations with the Atacama Large Millimeter/submillimeter Array (ALMA) detected far-infrared emission lines such as the [OIII] 88 \mu m line from galaxies at $z \sim 7 - 9$. Far-infrared lines can be used to probe the structure…

We investigated stellar maser sources with no IRAS counterpart at the radio, middle-infrared, and near-infrared wavelengths. A 43 GHz SiO maser search for 120 2MASS/MSX objects, and 10 OH 1612 MHz sources with no or a very faint MSX…

Astrophysics · Physics 2015-06-24 S. Deguchi , J. Nakashima , T. Miyata , Y. Ita

We report the first results from a survey for 1665, 1667, and 1720 MHz OH emission over a small region of the Outer Galaxy centered at $l \approx 105.0\deg , b \approx +1.0\deg$ . This sparse, high-sensitivity survey ($\Delta Ta \approx…

Astrophysics of Galaxies · Physics 2015-06-23 Ronald J. Allen , David E. Hogg , Philip D. Engelke

A systematic search for 22 GHz H2O megamaser emission is reported for 50 nearby (z < 0.15) FR I galaxies. No detection was obtained, implying that ultraluminous H2O masers (L_H2O>10^3 L_sun) must be rare in early-type galaxies with FR I…

Astrophysics · Physics 2007-05-23 C. Henkel , Y. P. Wang , H. Falcke , A. S. Wilson , J. A. Braatz

We have used the Fisher matrix formalism to quantify the prospects of detecting the z = 3.35 redshifted 21-cm HI power spectrum with the upcoming radio-imterferometric array OWFA. OWFA's frequency and baseline coverage spans comoving…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-28 Somnath Bharadwaj , Anjan Kumar Sarkar , Sk. Saiyad Ali

The 1612 MHz hydroxyl maser in circumstellar envelopes has long been thought to be pumped by 34.6um photons. Only recently, the Infrared Space Observatory has made possible spectroscopic observations which enable the direct confirmation of…

Astrophysics · Physics 2007-05-23 J. H. He , R. Szczerba , P. S. Chen , A. M. Sobolev

The HI mass function (HIMF) for galaxies in the local universe is constructed from the results of the Arecibo HI Strip Survey, a blind extragalactic survey in the 21cm line. The survey consists of two strips covering in total 65 square…

Astrophysics · Physics 2009-10-30 Martin Zwaan , Frank Briggs , David Sprayberry , Ertu Sorar

Using the Very Long Baseline Array (VLBA) we performed a high resolution OH maser survey in Galactic star-forming regions (SFRs). We observed all the ground state spectral lines: the main lines at 1665 and 1667 MHz and the satellite lines…

Solar and Stellar Astrophysics · Physics 2016-03-28 A. E. Ruiz-Velasco , D. Felli , V. Migenes , B. K. Wiggins

The Atacama Pathfinder Experiment (APEX) 12m telescope was used to observe the N=1-0, J=0-1 ground state transitions of OH+ at 909.1588 GHz with the CHAMP+ heterodyne array receiver. Two blended hyperfine structure transitions were detected…

Astrophysics of Galaxies · Physics 2015-05-18 F. Wyrowski , K. M. Menten , R. Guesten , A. Belloche

Galaxies detected in the 21-cm line of neutral hydrogen (HI) from the on-going Arecibo Legacy Fast ALFA (ALFALFA) blind extragalactic HI survey have been cross-correlated with Sloan Digital Sky Survey Data Release 7 (Abazajian et al. 2009)…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-13 M. C. Toribio , J. M. Solanes