English
Related papers

Related papers: Determination of the Sun's Offset from the Galacti…

200 papers

We present a maximum-likelihood analysis of galaxy-galaxy lensing effects in galaxy clusters and in the field. The aim is to determine the accuracy and robustness of constraints that can be obtained on galaxy halo properties in both…

Astrophysics · Physics 2009-11-10 Marceau Limousin , Jean Paul Kneib , Priyamvada Natarajan

This study is an investigation of the stellar density profile of the Galactic disc in the Anticentre direction. We select over 40,000 early A stars from IPHAS photometry in the Galactic longitude range 160 < l < 200 close to the equatorial…

By adopting the differential age method, we utilize selected 17832 luminous red galaxies (LRGs) from Sloan Digital Sky Survey Data Release Seven (SDSS DR7) covering redshift $0<z<0.4$ to measure Hubble parameters. Using a full spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-24 Cong Zhang , Han Zhang , Shuo Yuan , Siqi Liu , Tong-Jie Zhang , Yan-Chun Sun

Recent developments in instrumentation (e.g., in particular the Kepler and CoRoT satellites) provide a new opportunity to improve the models of stellar pulsations. Surface layers, rotation, and magnetic fields imprint erratic frequency…

Solar and Stellar Astrophysics · Physics 2015-06-04 M. Gruberbauer , D. B. Guenther , T. Kallinger

We conduct a small-scale pathfinding survey designed to identify the average polarization properties of the diffuse ISM locally at the lowest dust content regions. We perform deep optopolarimetric surveys within three $\sim 15' \times 15'$…

Astrophysics of Galaxies · Physics 2018-08-15 R. Skalidis , G. V. Panopoulou , K. Tassis , V. Pavlidou , D. Blinov , I. Komis , I. Liodakis

(Abridged) We infer the velocity distribution of radio pulsars by modelling their birth, evolution, and detection in large-scale 0.4 GHz pulsar surveys, and by comparing model distributions of measurable pulsar properties with survey data…

Astrophysics · Physics 2009-11-06 Z. Arzoumanian , D. F. Chernoff , J. M. Cordes

Galaxy-galaxy lensing measures the mean excess surface density DS(r) around a sample of lensing galaxies. We develop a method for combining DS(r) with the galaxy correlation function xi_gg(r) to constrain Omega_m and sigma_8, going beyond…

Astrophysics · Physics 2009-11-13 Jaiyul Yoo , Jeremy L. Tinker , David H. Weinberg , Zheng Zheng , Neal Katz , Romeel Davé

Although high-sensitivity surveys have revealed a number of highly dispersed pulsars in the inner Galaxy, none have so far been found in the Galactic centre (GC) region, which we define to be within a projected distance of 1~pc from Sgr~A*.…

High Energy Astrophysical Phenomena · Physics 2017-08-09 Kaustubh Rajwade , Duncan Lorimer , Loren Anderson

We present a direct measurement of the stellar velocity dispersion of the early-type lens galaxy D in the system MG2016+112 (z=1.004), determined from a spectrum obtained with the Echelle Spectrograph and Imager (ESI) on the W.M. Keck-II…

Astrophysics · Physics 2009-11-07 L. V. E. Koopmans , T. Treu

We analyze the X-ray scattering halos around three Galactic Anomalous X-ray Pulsars (AXPs) in order to constrain the distance and the optical extinction of each source. We obtain surface brightness distributions from EPIC-pn data obtained…

Astrophysics of Galaxies · Physics 2010-01-26 A. Rivera-Ingraham , M. H. van Kerkwijk

We address the question how accurately stellar ages can be determined by stellar evolution theory. We select the star with the best observational material available - our Sun. We determine the solar age by fitting solar evolution models to…

Astrophysics · Physics 2007-05-23 Achim Weiss , Helmut Schlattl

Millisecond Pulsars are second most abundant source population discovered by the Fermi-LAT. They might contribute non-negligibly to the diffuse emission measured at high latitudes by Fermi-LAT, the IDGRB. Gamma-ray sources also contribute…

High Energy Astrophysical Phenomena · Physics 2014-11-05 F. Calore , M. Di Mauro , F. Donato

We compile and analyze ~200 trigonometric parallaxes and proper motions of molecular masers associated with very young high-mass stars. These measurements strongly suggest that the Milky Way is a four-arm spiral. Fitting log-periodic…

Due to the inhomogeneity of electron number density, radio waves emitted by pulsars undergo scattering as they pass through the interstellar medium (ISM). However, a connection between large-scale pulsar scattering data and the structure of…

Astrophysics of Galaxies · Physics 2025-02-14 Qiuyi He , Xun Shi , Guangxing Li

We applied the currently most comprehensive version of the statistical-parallax technique to derive kinematical parameters of the maser sample with 136 sources. Our kinematic model comprises the overall rotation of the Galactic disk and the…

Astrophysics of Galaxies · Physics 2017-06-21 A. S. Rastorguev , N. D. Utkin , M. V. Zabolotskikh , A. K. Dambis , A. T. Bajkova , V. V. Bobylev

We revisit the population of normal pulsars in the Galactic field in an `evolutionary' approach. By comparing the distributions of various parameters of synthetic pulsars detectable by the Parkes Multibeam Pulsar Survey, the Pulsar Arecibo…

High Energy Astrophysical Phenomena · Physics 2020-12-25 Anirban Chakraborty , Manjari Bagchi

As the number of known Galactic structures mounts thanks to the Gaia Space Telescope, it is now pertinent to study methods for disentangling structures occupying the same regions of the Milky Way. Indeed, understanding the precise form of…

Astrophysics of Galaxies · Physics 2024-03-14 Ziyuan Yin , Austin Hinkel

The first results of the construction of a 3D reddening map for stars within 1600 pc of the Sun are presented. Analysis of the distribution of 70 million stars from the 2MASS catalog with the most accurate photometry on the (J-Ks) - Ks…

Solar and Stellar Astrophysics · Physics 2016-07-06 George Gontcharov

Aims. We present a study of the distribution of stellar ages in the Orion Nebula Cluster (ONC) based on accurate HST photometry taken from the HST Treasury Program observations of the ONC utilizing the most recent estimate of the cluster's…

Astrophysics of Galaxies · Physics 2015-05-30 M. Reggiani , M. Robberto , N. Da Rio , M. R. Meyer , D. R. Soderblom , L. Ricci

The distribution of young open clusters in the Galactic plane within 3 kpc from the Sun suggests the existence of the outer ring R1R2' in the Galaxy. The optimum value of the solar position angle with respect to the major axis of the bar,…

Astrophysics of Galaxies · Physics 2016-02-03 A. M. Melnik , P. Rautiainen , E. V. Glushkova , A. K. Dambis