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相关论文: Selection of the SIM Astrometric Grid

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We present Spitzer/IRAC observations at 3.6 and 4.5 microns along with optical data from the Local Group Galaxies Survey to investigate the evolved stellar population of the Local Group dwarf irregular galaxy WLM. These observations provide…

天体物理学 · 物理学 2008-11-26 Dale C. Jackson , Evan D. Skillman , Robert D. Gehrz , Elisha Polomski , Charles E. Woodward

The past two Decadal Surveys in Astronomy and Astrophysics recommended the completion of a space-based interferometry mission, known today as SIM PlanetQuest, for its unique ability to detect and characterize nearby rocky planets (Bahcall…

Using combinations of H\alpha, ultraviolet (UV), and infrared (IR) emission, we estimate the star formation rate (SFR) surface density, \Sigma_SFR, at 1 kpc resolution for 30 disk galaxies that are targets of the IRAM HERACLES CO survey. We…

Close to 100 per cent of massive stars are thought to be in binary systems. The multiplicity of massive stars seems to be intrinsically linked to their formation and evolution, and Massive Young Stellar Objects are key in observing this…

We present a new fully data-driven algorithm that uses photometric data from the Canada-France-Imaging-Survey (CFIS; $u$), Pan-STARRS 1 (PS1; $griz$), and Gaia ($G$) to discriminate between dwarf and giant stars and to estimate their…

We have studied the effects of various initial mass functions (IMFs) on the chemical evolution of the Sagittarius dwarf galaxy (Sgr). In particular, we tested the effects of the integrated galactic initial mass function (IGIMF) on various…

We present a new census of Galactic and extragalactic symbiotic stars (SySts). This compilation contains 323 known and 87 candidate SySts. Of the confirmed SySts, 257 are Galactic and 66 extragalactic. The spectral energy distributions…

太阳与恒星天体物理 · 物理学 2019-02-06 Stavros Akras , Lizette Guzman-Ramirez , Marcelo L. Leal-Ferreira , Gerardo Ramos-Larios

For a sample of star forming galaxies in the redshift interval 0.15$<$z$<$0.3, we study how both the relative strength of the AGN infra-red emission, compared to that due to the star formation (SF), and the numerical fraction of AGNs,…

Mass estimates of K giants are generally very uncertain. Traditionally, stellar masses of single field stars are determined by comparing their location in the Hertzsprung-Russell diagram with stellar evolutionary models. Applying an…

天体物理学 · 物理学 2009-11-13 D. Stello , H. Bruntt , H. Preston , D. Buzasi

Context: The current sample of known brown dwarfs (BDs) around FGK-stars is only of the order of a hundred. The ongoing ESA mission Gaia has already collected its nominal 5 yr of mission data and might operate up to 10 yr. Aims: Using…

太阳与恒星天体物理 · 物理学 2022-05-25 B. Holl , M. Perryman , L. Lindegren , D. Segransan , M. Raimbault

We use a semianalytic galaxy catalogue constructed from the Millennium Simulation to study the satellites of isolated galaxies in the LCDM cosmogony. This sample (~80,000$ bright primaries, surrounded by ~178,000 satellites) allows the…

天体物理学 · 物理学 2009-11-13 L. V. Sales , J. F. Navarro , D. G. Lambas , S. D. M. White , D. J. Croton

The X-ray Imaging Spectroscopy Mission (XRISM) provides the best spectral resolution with which to study Sulfur (S) K-shell photoabsorption features from the interstellar medium (ISM). For the first time, we demonstrate the high-signal…

Massive MIMO is a promising technique to increase the spectral efficiency of cellular networks, by deploying antenna arrays with hundreds or thousands of active elements at the base stations and performing coherent beamforming. A common…

信息论 · 计算机科学 2014-11-21 Emil Björnson , Erik G. Larsson , Mérouane Debbah

Using a spectroscopically confirmed sample of M-giants, M-dwarfs and quasars from the LAMOST survey, we assess how well WISE $\&$ 2MASS color-cuts can be used to select M-giant stars. The WISE bands are very efficient at separating M-giants…

Deep optical imaging is used to study time-domain properties of young brown dwarfs in sigma Orionis over typical rotational time-scales and to search for new substellar and planetary-mass cluster members. We used VIMOS at the VLT to monitor…

太阳与恒星天体物理 · 物理学 2017-12-13 P. Elliott , A. Scholz , R. Jayawardhana , J. Eisloffel , E. M. Hebrard

Young M-type binaries are particularly useful for precise isochronal dating by taking advantage of their extended pre-main sequence evolution. Orbital monitoring of these low-mass objects becomes essential in constraining their fundamental…

M giants recovered from the Two Micron All-Sky Survey (2MASS) have recently been used to map the position and velocity distributions of tidal debris from the Sagittarius (Sgr) dwarf spheroidal galaxy entirely around the Galaxy. We compare…

天体物理学 · 物理学 2011-05-05 David R. Law , Kathryn V. Johnston , Steven R. Majewski

We have identified a first group of 33 new candidates for symbiotic stars (SySt) of the accreting-only variety among the 600,255 stars so far observed by the GALAH high-resolution spectroscopic survey of the Southern Hemisphere, more than…

[abridged] We carry out numerical simulations to gauge the Gaia potential for precision astrometry of exoplanets orbiting a sample of known dM stars within 30 pc from the Sun. (1) It will be possible to accurately determine orbits and…

地球与行星天体物理 · 物理学 2015-06-17 A. Sozzetti , P. Giacobbe , M. G. Lattanzi , G. Micela , R. Morbidelli , G. Tinetti

One of the most promising methods of discovering nearby, low-mass planets in the habitable zones of stars is the precision radial velocity technique. However, there are many challenges that must be overcome to efficiently detect…

地球与行星天体物理 · 物理学 2015-06-15 Michael Bottom , Philip S. Muirhead , John Asher Johnson , Cullen H. Blake