CMD help

What's this CMD is a set of routines that provide interpolated isochrones in a grid, together with derivatives such as luminosity functions, simulated star clusters, etc. The photometry can be produced for many different broad- and intermediate-band systems, including non-standard ones. The effect of circumstellar dust has been added in version 2.0, star-to-star interstellar extinction in version 2.1.

The underlying code is the same used in the papers

Girardi L., Dalcanton J., Williams B., de Jong R., Gallart C., Monelli M., Groenewegen M.A.T., Holtzman J.A., Olsen K.A.G., Seth A.C., Weisz D.R., 2008, PASP 120, 583 Revised bolometric corrections and extinction coefficients for the ACS and WFPC2 photometric systems

Marigo, P., Girardi, L., Bressan, A., Groenewegen, M.A.T., Silva, L., & Granato, G.L., 2008, Astronomy and Astrophysics 482, 883 Evolution of asymptotic giant branch stars. II Optical to far-infrared isochrones with improved TP-AGB models

Girardi, L., Bertelli, G., Bressan, A., Chiosi, C., Groenewegen, M. A. T., Marigo, P., Salasnich, B., & Weiss, A. 2002, Astronomy and Astrophysics 391, 195 Theoretical isochrones in several photometric systems. I. Johnson-Cousins-Glass, HST/WFPC2, HST/NICMOS, Washington, and ESO Imaging Survey filter sets

Girardi, L., Grebel, E. K., Odenkirchen, M., & Chiosi, C. 2004, Astronomy and Astrophysics 422, 205 Theoretical isochrones in several photometric systems. II. The Sloan Digital Sky Survey ugriz system

Bonatto, Ch., Bica, E., & Girardi, L. 2004, Astronomy and Astrophysics 415, 571 Theoretical isochrones compared to 2MASS observations: Open clusters at nearly solar metallicity

(and in many others). Please give a look at these papers, as well as to the static webpages of and, for a complete description of the output, and a complete list of references.

CMD is being extended/updated every few months. The latest version is always linked in .

Isochrones The output format of isochrones is basically the same one described in the "TABLES OF ISOCHRONES" section of this readme.txt file, but for a few updates:
  • FLUM has been replaced by int_IMF, which is the integral of the IMF under consideration (as selected in the form, in number of stars, and normalised to a total mass of 1 M☉) from 0 up to the current M_ini. Differences between 2 values of int_IMF give the absolute number of stars occupying that isochrone section per unit mass of stellar population initially born, as expected for the selected IMF.
  • The new colums C/O, M_hec, period, pmode, logMdot were added. They refer mainly to the TP-AGB evolution: C/O is the photospheric C/O ratio (the ZAMS value is printed before the TP-AGB), M_hec is the H-exhausted core mass on the TP-AGB (and is set to 0 before the TP-AGB), period is the LPV period in days, pmode is the pulsation mode (1=first overtone, 0=fundamental mode), and logMdot is the log10 of the mass loss rate in Msun/year. These quantities are accurate only for the TP-AGB phase (when M_hec>0).
  • New in CMD v2.5: Evolutionary stages are printed in the last column, stage. The labels are: 0=PMS, 1=MS, 2=SGB, 3=RGB, (4,5,6)=different stages of CHEB, 7=EAGB, 8=TPAGB.
  • Luminosity functions In CMD, the Luminosity function (LF) gives the absolute number of stars occupying each magnitude bin per unit mass of the stellar population initially born, for a given IMF. For the selected photometric system and IMF, the form allows you to choose the range of absolute magnitudes (from faintest to brightest) and the width of magnitude bins. The output files will then simultaneously provide LFs for all filters in the selected photometric system, together with the LF in bolometric magnitudes.
    SSP integrated magnitudes In CMD, the integrated magnitudes of single-burst stellar population (SSP) are computed for a unit mass of the stellar population initially born, for the given IMF. They are computed for all filters in the selected photometric system. SSP integrated magnitudes are derived assuming stars populate continuously the entire isochrone, and hence do not include the stochastic variations in the integrated magnitudes (and colours) that are typical of real SSPs (star clusters).

    This service is mantained by Léo Girardi at the Osservatorio Astronomico di Padova.
    Questions, comments and special requests should be directed to leo.girardi@oapd·inaf·it .
    Last modified: Feb 17, 2008