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相关论文: Revised distances to several Bok globules

200 篇论文

Accurate distances to local molecular clouds are critical for understanding the star and planet formation process, yet distance measurements are often obtained inhomogeneously on a cloud-by-cloud basis. We have recently developed a method…

We present mid-infrared (10.4 \micron, 11.7 \micron, and 18.3 \micron) imaging intended to locate and characterize the suspected protostellar components within the Bok globule CB54. We detect and confirm the protostellar status for the…

天体物理学 · 物理学 2009-06-23 David R. Ciardi , Cynthia Gomez Martin

Context: The role of magnetic fields in the star formation process is a contentious matter of debate. In particular, no clear observational proof exists of a general influence by magnetic fields during the initial collapse of molecular…

太阳与恒星天体物理 · 物理学 2014-04-23 Gesa Bertrang , Sebastian Wolf , Himadri S. Das

We determine the extinction law through Cep OB3b, a young cluster of 3000 stars undergoing gas dispersal. The extinction is measured toward 76 background K giants identified with MMT/Hectospec spectra. Color excess ratios were determined…

CO observations allow estimations of the gas content of molecular clouds, which trace the reservoir of cold gas fuelling star formation, as well as to determine extinction via H$_2$ column density, N(H$_2$). Here, we studied millimetric and…

The principle of the background-eliminated extinction-parallax (BEEP) method is examining the extinction difference between on- and off-cloud regions to reveal the extinction jump caused by molecular clouds, thereby revealing the distance…

星系天体物理 · 物理学 2021-11-24 Qing-Zeng Yan , Ji Yang , Yang Su , Yan Sun , Ye Xu , Hongchi Wang , Xin Zhou , Chen Wang

We test two different methods of using near-infrared extinction to estimate distances to dark clouds in the first quadrant of the Galaxy using large near infrared (2MASS and UKIDSS) surveys. VLBI parallax measurements of masers around…

星系天体物理 · 物理学 2015-06-04 Jonathan B. Foster , Joseph J. Stead , Robert A. Benjamin , Melvin G. Hoare , James M. Jackson

We searched the Sloan Digital Sky Survey for outer halo globular clusters (GCs) around M31. Our search of non-stellar objects, within the limits 0.3 < (g-i)o < 1.5 and 14.0 < ro < 19.0 concentrated in some remote areas of the extended halo,…

星系天体物理 · 物理学 2015-06-12 Graziella di Tullio Zinn , Robert Zinn

We report the most sensitive water maser survey towards Bok globules to date, using NASA's 70m antenna in Robledo de Chavela (Spain). We observed 207 positions within the CB catalog with a higher probability of harboring a young star, using…

天体物理学 · 物理学 2008-11-26 Jose F. Gomez , Itziar de Gregorio-Monsalvo , Olga Suarez , Thomas B. H. Kuiper

We report the first determination of a distance bracket for the high-velocity cloud (HVC) complex C. Combined with previous measurements showing that this cloud has a metallicity of 0.15 times solar, these results provide ample evidence…

Using the Planck far-infrared and Arecibo GALFA 21-cm line surveys, we identified a set of isolated interstellar clouds (approximately degree-sized on the sky and comprising 100 solar masses) and assessed the ratio of gas mass to dust mass.…

星系天体物理 · 物理学 2015-10-07 William T. Reach , Carl Heiles , Jean-Philippe Bernard

Utilising the unique location of red clump giants on colour-magnitude diagrams obtained from various near-IR surveys, we derived specific reddening-distance relations towards 119 Galactic novae for which independent reddening measurements…

太阳与恒星天体物理 · 物理学 2017-08-30 Aykut Özdönmez , Tolga Güver , Antonio Cabrera-Lavers , Tansel Ak

Optical high-resolution spectra of five central stars of planetary nebulae (CSPN) in the Galactic Bulge have been obtained with Keck/HIRES in order to derive their parameters. Since the distance of the objects is quite well known, such a…

Using infrared photometric data extracted from the 2MASS, IRAS and MSX databases, 142 suspected young stellar objects (YSOs) are selected from about 2 million stars in the Camelopardalis segment of the Milky Way limited by Galactic…

天体物理学 · 物理学 2009-06-25 V. Straizys , V. Laugalys

Circumstellar discs are expected to be the nursery of planets. Grain growth within such discs is the first step in the planet formation process. The Bok globule CB 26 harbours such a young disc. We present a detailed model of the edge-on…

We present a 8 deg x 6 deg, high resolution extinction map of the Pipe nebula using 4.5 million stars from the Two Micron All Sky Survey (2MASS) point source catalog. The use of NICER, a robust and optimal technique to map the dust column…

天体物理学 · 物理学 2009-11-11 Marco Lombardi , Joao Alves , Charles J. Lada

Understanding the distribution and properties of molecular clouds is crucial for tracing the structure and evolution of the interstellar medium and the large-scale morphology of the Milky Way. Here we present an all-sky catalog of 3,345…

星系天体物理 · 物理学 2025-09-10 Tao Wang , Haibo Yuan , Bingqiu Chen , Guangxing Li , Bowen Huang , Helong Guo , Ruoyi Zhang

By collecting distances from the literature, a set of 73 planetary nebulae with mean distances of high accuracy is derived. This sample is used for recalibration of the mass-radius relationship, used by many statistical distance methods. An…

天体物理学 · 物理学 2009-11-06 T. Bensby , I. Lundström

This investigation presents a photometric study of the Galactic structure toward the Carina arm tangent. The field is located between 280 deg and 286 deg galactic longitude and -4 deg to 4 deg galactic latitude. All currently available…

星系天体物理 · 物理学 2013-07-17 N. Kaltcheva , V. Golev

A most desirable feature of a standard candle to estimate astronomical distances is robustness against changes in metallicity and age. It is argued that the radii of main sequence stars with spectral types from solar to A0 show predictable…

天体物理学 · 物理学 2009-10-31 Carlos Allende Prieto