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相关论文: A Determination of the Luminosity Function of DA W…

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We have developed a Monte Carlo method to compute the luminosity function of galaxies, based on photometric redshifts, which takes into account the non-gaussianity of the probability functions, and the presence of degenerate solutions in…

天体物理学 · 物理学 2009-11-07 Micol Bolzonella , Roser Pello' , Dario Maccagni

We present a comparative analysis of atmospheric parameters obtained with the so-called photometric and spectroscopic techniques. Photometric and spectroscopic data for 1360 DA white dwarfs from the Sloan Digital Sky Survey (SDSS) are used,…

太阳与恒星天体物理 · 物理学 2015-06-23 C. Genest-Beaulieu , P. Bergeron

We computed Doppler beaming factors for DA, DB, and DBA white dwarf models, as well as for main sequence and giant stars covering the transmission curves of the Sloan, UBVRI, HiPERCAM, Kepler, TESS, and Gaia photometric systems. The…

太阳与恒星天体物理 · 物理学 2020-09-30 A. Claret , E. Cukanovaite , K. Burdge , P. -E. Tremblay , S. Parsons , T. R. Marsh

Over the years, several methods have been proposed to compute galaxy luminosity functions, from the most simple ones -counting sample objects inside a given volume- to very sophisticated ones -like the C- method, the STY method or the…

天体物理学 · 物理学 2009-11-11 E. M. Geijo , S. Torres , J. Isern , E. Garcia-Berro

Using a new grid of models of cooling white dwarfs, we calculate isochrones and luminosity functions in the Johnson-Kron/Cousins and HST filter sets for systems containing old white dwarfs. These new models incorporate a non-grey atmosphere…

Dark acoustic oscillations (DAOs) in the matter power spectrum can arise in many different dark sector models, and can imprint on a variety of cosmological observables. In this work we use measurements of the galactic UV luminosity function…

宇宙学与河外天体物理 · 物理学 2025-12-02 Jared Barron , David Curtin , Hongwan Liu , Julian Munoz , Sandip Roy

We present the results for the galaxy luminosity function as estimated from the Durham/UKST Galaxy Redshift Survey. This survey is magnitude limited to bj = 17, contains 2500 galaxies sampled at a rate of one in three and surveys a 4 x 10^6…

天体物理学 · 物理学 2009-10-30 A. Ratcliffe , T. Shanks , Q. A. Parker , R. Fong

We have established a network of 19 faint (16.5 mag $< V < $19 mag) northern and equatorial DA white dwarfs as spectrophotometric standards for present and future wide-field observatories. Our analysis infers SED models for the stars that…

The white dwarf luminosity function, which provides information about their cooling, has been measured with high precision in the past few years. Simulations that include well known Standard Model physics give a good fit to the data. This…

高能物理 - 唯象学 · 物理学 2015-06-15 Herbert K. Dreiner , Jean-François Fortin , Jordi Isern , Lorenzo Ubaldi

We present a measurement of the quasar luminosity function in the range 0.68<z<4 down to extinction corrected magnitude g_dered=22.5, using a simple and well understood target selection technique based on the time-variability of quasars.…

We present a comprehensive analysis of DB white dwarfs drawn from the Sloan Digital Sky Survey, based on model fits to $ugriz$ photometry and medium resolution spectroscopy from the SDSS. We also take advantage of the exquisite…

太阳与恒星天体物理 · 物理学 2019-09-25 C. Genest-Beaulieu , P. Bergeron

We derive the disk I-band luminosity function from the Zheng et al. sample of \~1400 disk M dwarfs observed with the Hubble Space Telescope. We adopt a Galactic-height-dependent color-magnitude relation to account for the metallicity…

天体物理学 · 物理学 2014-10-13 Zheng Zheng , Chris Flynn , Andrew Gould , John N. Bahcall , Samir Salim

Context. The advent of the Extremely Large Telescope (ELT) will increase the collecting area by more than an order of magnitude compared to the individual Unit Telescopes of the Very Large Telescope (VLT). Fainter spectrophotometric…

天体物理仪器与方法 · 物理学 2025-08-11 N. P. Gentile Fusillo , S. Moehler , N. Przybilla , A. K. Elms , P. -E. Tremblay , W. Kausch , F. Kerber

The spectral energy distributions for pure-hydrogen (DA) hot white dwarfs can be accurately predicted by model atmospheres. This makes it possible to define spectrophotometric calibrators by scaling the theoretical spectral shapes with…

太阳与恒星天体物理 · 物理学 2015-05-13 C. Allende Prieto , I. Hubeny , J. A. Smith

We present progress results of a new survey for bright QSOs (V<14.5, R<15.4, B_J<15.2) covering the whole sky at |b|>30. The surface density of QSOs brighter than B_J=14.8 turns out to be $2.9 \pm 0.8 \cdot 10^{-3} deg^{-2}$. The optical…

天体物理学 · 物理学 2007-05-23 S. Cristiani , A. Grazian , A. Omizzolo

We describe a new multi-colour proper motion survey for cool white dwarfs (CWDs). The observational database consists of ~300 digitally scanned Schmidt plates in ESO/SERC field 287. The entire survey procedure, from the raw Schmidt plate…

天体物理学 · 物理学 2009-10-31 R. A. Knox , M. R. S. Hawkins , N. C Hambly

Recent studies have derived quasar luminosity functions (QLFs) at various redshifts. However, the faint side of the QLF at high redshifts is still too uncertain. An accurate estimate of the survey completeness is essential to derive an…

We present a study of the iron abundance pattern in hot hydrogen-rich (DA) white dwarfs. The study is based on new and archival far ultraviolet spectroscopy of a sample of white dwarfs in the temperature range 30,000 K < T_eff < 64,000 K.…

天体物理学 · 物理学 2008-11-26 Stephane Vennes , Pierre Chayer , Jean Dupuis , Thierry Lanz

A total of 81 DA white dwarfs have been observed with the Cosmic Origins Spectrograph on the Hubble Space Telescope in a snapshot program. The targets were selected to be in the $T_{\rm eff}$ range from 17000 - 25000 K, where optical metal…

太阳与恒星天体物理 · 物理学 2012-09-27 Detlev Koester , Boris Gänsicke , Jonathan Girven , Jay Farihi

White dwarf studies carry significant implications across multiple fields of astrophysics, including exoplanets, supernova explosions, and cosmological investigations. Thus, accurate determinations of their fundamental parameters (Teff and…