مقاله Anchors for the cosmic distance scale: the Cepheid QZ Normae in the open cluster NGC 6067 : تی پی بین

خلاصه مقاله

Cepheids are key to establishing the cosmic distance scale. Therefore it’s important to assess the viability of QZ Nor, V340 Nor, and GU Nor as calibrators for Leavitt’s law via their purported membership in the open cluster NGC 6067. The following suite of evidence confirms that QZ Nor and V340 Nor are members of NGC 6067, whereas GU Nor likely lies in the foreground: (i) existing radial velocities for QZ Nor and V340 Nor agree with that established for the cluster ( −39.4±0.2(σx¯)±1.2(σ) km/s ) to within 1 km/s, whereas GU Nor exhibits a markedly smaller value; (ii) a steep velocity-distance gradient characterizes the sight-line toward NGC 6067, thus implying that objects sharing common velocities are nearly equidistant; (iii) a radial profile constructed for NGC 6067 indicates that QZ Nor is within the cluster bounds, despite being 20′ from the cluster center; (iv) new BVJH photometry for NGC 6067 confirms the cluster lies d=1.75±0.10 kpc distant, a result that matches Wesenheit distances computed for QZ Nor/V340 Nor using the Benedict et al. (Astron. J. 133:1810, 2007, HST parallaxes) calibration. QZ Nor is a cluster Cepheid that should be employed as a calibrator for the cosmic distance scale.

نویسندگان

D. Majaess [ Halifax, Nova Scotia, Canada ]

L. Sturch [ Dept. of Astronomy, Institute for Astronomical Research, Boston University, 725 Commonwealth Ave, Boston, MA, 02215, USA ]

C. Moni Bidin [ Instituto de Astronomía, Universidad Católica del Norte, Av. Angamos, 0610, Antofagasta, Chile ]

M. Soto [ Departamento de Física, Universidad de La Serena, Benavente 980, La Serena, Chile ]

W. Gieren [ Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción, Chile ]

کلمات کلیدی

Stars Variables Cepheids

آدرس این مقاله

آدرس مستقیم دسترسی به این مقاله

مشخصات کنفرانس

مشاهده مقالات

Astrophysics and Space Science 2013

Astrophysics and Space Science publishes original contributions and invited reviews covering the entire range of astronomy, astrophysics, astrophysical cosmology, planetary and space science and the astrophysical aspects of astrobiology. This includes both observational and theoretical research, the techniques of astronomical instrumentation and data analysis and astronomical space instrumentation. We particularly welcome papers in the general fields of high-energy astrophysics, astrophysical and astrochemical studies of the interstellar medium including star formation, planetary astrophysics, the formation and evolution of galaxies and the evolution of large scale structure in the Universe. Papers in mathematical physics or in general relativity which do not establish clear astrophysical applications will no longer be considered.The journal also publishes topically selected special issues in research fields of particular scientific interest. These consist of both invited reviews and original research papers. Conference proceedings will not be considered. All papers published in the journal are subject to thorough and strict peer-reviewing.Astrophysics and Space Science features short publication times after acceptance and colour printing free of charge.Commonly used title abbreviations: Astrophys Space Sci, Ap SS

حوزه های تحت پوشش : Astrophysics and Astroparticles Astronomy, Observations and Techniques Cosmology Extraterrestrial Physics, Space Sciences Astrobiology