English
Related papers

Related papers: A maximum likelihood method for fitting colour-mag…

200 papers

We have developed the techniques required to use the optimal photometry algorithm of Naylor (1998) to create colour-magnitude diagrams with well defined completeness functions. To achieve this we first demonstrate that the optimal…

Astrophysics · Physics 2009-11-07 Tim Naylor , E. J. Totten , R. D. Jeffries , M. Pozzo , C. R. Devey , S. A. Thompson

We present a new technique to fit color-magnitude diagrams of open clusters based on the Cross-Entropy global optimization algorithm. The method uses theoretical isochrones available in the literature and maximizes a weighted likelihood…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 H. Monteiro , W. S. Dias , T. C. Caetano

The determination of galaxy merger fraction of field galaxies using automatic morphological indices and photometric redshifts is affected by several biases if observational errors are not properly treated. Here, we correct these biases…

Astrophysics · Physics 2009-11-13 C. López-Sanjuan , C. E. García-Dabó , M. Balcells

A deep understanding of the Milky Way galaxy, its formation and evolution requires observations of huge numbers of stars. Stellar photometry, therefore, provides an economical method to obtain intrinsic stellar parameters. With the addition…

Solar and Stellar Astrophysics · Physics 2019-01-30 Louise M. Howes , Lennart Lindegren , Sofia Feltzing , Ross P. Church , Thomas Bensby

We present new isochrone fits to colour-magnitude diagrams of the Galactic globular cluster NGC\,6205 (M13). We utilise 34 photometric bands from the ultraviolet to mid-infrared by use of data from the {\it HST}, {\it Gaia} DR2, SDSS,…

Astrophysics of Galaxies · Physics 2020-08-25 G. A. Gontcharov , M. Yu. Khovritchev , A. V. Mosenkov

The Bayesian isochrone fitting using the Markov chain Monte Carlo algorithm is applied, to derive the probability distribution of the parameters age, metallicity, reddening, and absolute distance modulus. We introduce the \texttt{SIRIUS}…

We present new isochrone fits to colour-magnitude diagrams of the Galactic globular cluster NGC 5904 (M5). We utilise 29 photometric bands from the ultraviolet to mid-infrared by use of the data from the {\it Hubble Space Telescope}, {\it…

Astrophysics of Galaxies · Physics 2019-10-25 George A. Gontcharov , Aleksandr V. Mosenkov , Maxim Yu. Khovritchev

The forthcoming generation of galaxy redshift surveys will sample the large-scale structure of the Universe over unprecedented volumes with high-density tracers. This advancement will make robust measurements of three-point clustering…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-29 Andrea Oddo , Emiliano Sefusatti , Cristiano Porciani , Pierluigi Monaco , Ariel G. Sánchez

(ABRIDGED) We assess the systematic uncertainties in (young) cluster age, mass, and - to a lesser extent - extinction and metallicity determinations, based on broad-band imaging observations with the Hubble Space Telescope. Our aim here is…

Using mock spectra based on Vazdekis/MILES library fitted within the wavelength region 3600-7350\AA, we analyze the bias and scatter on the resulting physical parameters induced by the choice of fitting algorithms and observational…

Astrophysics of Galaxies · Physics 2018-05-23 Junqiang Ge , Renbin Yan , Michele Cappellari , Shude Mao , Hongyu Li , Youjun Lu

We present a new method for the evaluation of the age and age-spread among pre-main-sequence (PMS) stars in star-forming regions in the Magellanic Clouds, accounting simultaneously for photometric errors, unresolved binarity, differential…

Astrophysics of Galaxies · Physics 2015-05-19 Nicola Da Rio , Dimitrios A. Gouliermis , Mario Gennaro

We present a simple approach for obtaining robust values of astrophysical parameters from the observed colour-magnitude diagrams (CMDs) of star clusters. The basic inputs are the Hess diagram built with the photometric measurements of a…

Solar and Stellar Astrophysics · Physics 2015-05-20 C. Bonatto , F. Campos , S. O. Kepler , E. Bica

We present our new, fully-automated method to detect and measure the ages of star clusters in nearby galaxies, where individual stars can be resolved. The method relies purely on statistical analysis of observations and Monte-Carlo…

Obtaining accurately calibrated redshift distributions of photometric samples is one of the great challenges in photometric surveys like LSST, Euclid, HSC, KiDS, and DES. We present an inference methodology that combines the redshift…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-09 M. M. Rau , C. B. Morrison , S. J. Schmidt , S. Wilson , R. Mandelbaum , Y. Y. Mao

Astronomical data is often uncertain with errors that are heteroscedastic (different for each data point) and covariant between different dimensions. Assuming that a set of D-dimensional data points can be described by a (D - 1)-dimensional…

Instrumentation and Methods for Astrophysics · Physics 2015-10-21 A. S. G. Robotham , D. Obreschkow

Fitting whole spectra at intermediate spectral resolution (R = 1000 -- 3000), to derive physical properties of stellar populations, appears as an optimized alternative to methods based on spectrophotometric indices: it uses all the…

Astrophysics · Physics 2009-11-13 M. Koleva , Ph. Prugniel , P. Ocvirk , D. Le Borgne , C. Soubiran

We present two different halo-independent methods to assess the compatibility of several direct dark matter detection data sets for a given dark matter model using a global likelihood consisting of at least one extended likelihood and an…

High Energy Physics - Phenomenology · Physics 2016-10-26 Graciela B. Gelmini , Ji-Haeng Huh , Samuel J. Witte

We introduce a new method for solving maximum likelihood problems through variational calculus, and apply it to the case of recovering an unknown star formation history, $SFR(t)$, from a resulting HR diagram. This approach allows a totally…

Astrophysics · Physics 2009-10-30 X. Hernandez , David Valls-Gabaud , Gerard Gilmore

Accurately determining the age of H\,{ii} regions and the stars they host is as important as it is challenging. Historically the most popular method has been isochrone fitting to Hertzsprung-Russell Diagrams or Colour-Magnitude Diagrams.…

Solar and Stellar Astrophysics · Physics 2020-08-19 H. F. Stevance , J. J. Eldridge , A. McLeod , E. R. Stanway , A. A. Chrimes

This paper provides a detailed comparison of the differences in parameters derived for a star cluster from its color-magnitude diagrams depending on the filters and models used. We examine the consistency and reliability of fitting three…

Solar and Stellar Astrophysics · Physics 2015-06-23 Shane Hills , Ted von Hippel , Stephane Courteau , Aaron M. Geller
‹ Prev 1 2 3 10 Next ›