Synthetic HB Generator

What is this?

This page allows one to a synthetic horizontal branch (SHB) model for any [Fe/H] within the bounds of the computed grid (via a web interface to shb). Other input parameters include the number of stars and the mass distribution. All masses should be entered in Msol. For more on shb see the Programs page.

The program creates a synthetic HB by drawing stars at random from a Gaussian distribution. The Gaussian distribution is defined by the average mass and the dispersion. The upper bound of the mass distribution is defined by the user (it can be estimated from the mass at the tip of the RGB in a particular isochrone). The lower bound is defined by the He core mass (~0.5 Msol) and is a function of the metallicity.

Input Parameters: To avoid problems, please include a decimal point, e.g. "-1.0" instead of "-1".

[Fe/H]=		Available range is -2.5 < [Fe/H] < +0.5
[α/Fe]=	-0.2 0 (scaled-solar) +0.2 +0.4 +0.6 +0.8	Fixed options for [α/Fe].
Colors:	--Synthetic-- Bessell+2MASS HST ACS-WFC HST WFPC2 SDSS ugriz ACS GGC --Empirical-- BV(RI)c Stromgren ACS GGC	Choice of photometric system. Filters listed in table below.
Number of stars=		Maximum allowed number is 106.
Max. HB mass=		Maximum allowed stellar mass on the HB (Msol).
Ave. HB mass=		Average stellar mass on the HB (Msol).
Mass dispersion=		Dispersion in Gaussian mass distribution (Msol).

Phot. System	Filters
BV(RI)c	B	V	Rc	Ic
Stromgren	u	v	b	y	c1	m1
SDSS	u	g	r	i	z
Bessell + 2MASS	U	B	V	Rc	Ic	J	H	Ks
HST ACS-WFC	F435W	F475W	F555W	F606W	F625W	F775W	F814W	F850L
HST WFPC2	F336W	F439W	F450W	F555W	F606W	F791W	F814W	F850L
ACS GGC Survey	B	V	I	F606W	F814W	F606W	F814W