README file for "Set II" data tables

This dataset gives a full summary of the main photometric quantities and the detailed Spectral Energy Distribution (SED) for the Simple Stellar Population (SSP) models.
Credit to these models should be acknowledged referring to:
Buzzoni, A.: ``Evolutionary Population Synthesis Models in Stellar Systems.I. A Global Approach'', 1989, Astrophys. Journal Suppl. Series, 71, 817.

Each table begins with a header reporting the general quantities as in the following example:

(1) (2) (3) (4) (5) (6) (7)

Z [Fe/H] Y s m.loss Minf HB

0.0001 -2.27 0.23 2.35 0.3 0.1 R

(1): Metallicity. We explore the range for Z = 0.0001, 0.001, 0.01, 0.017 (solar value), 0.03, and 0.1.

(2): Iron-to-Hydrogen abundance relative to the Sun (by definition [Fe/H](sun) = 0)

(3): Helium abundance. The value of Y is 0.23 for Z = 0.0001 and 0.001 models, Y = 0.25 for Z = 0.01, 0.017, 0.03, and Y = 0.35 for Z = 0.1. The relevant equivalence X+Y+Z = 1 holds, from which the Hydrogen abundance can be derived.

(4): IMF power-law index. We assume dN = A M**(-s) dM. For a Salpeter IMF s=2.35. In addition, the case of s = 1.35 (giant-dominated SSPs) and 3.35 (dwarf-dominated SSPs) is considered.

(5): Mass loss coefficient η in the Reimers (1975) formula (see Buzzoni 1989). This parameter mainly affects the AGB luminosity extension. A larger value of η means a more enhanced mass loss (that is a fainter AGB tip). The empirical tuning for low-Z SSPs indicates a typical value about 1/3 (see Iben and Renzini, 1983 ARAA, 21, 271). In our model grid we assume η = 0.3 and 0.5.

(6): Lower mass limit for the IMF, in solar unit. Always fixed in the models at 0.1 M_sun.

(7): Horizontal Branch morphology for the 15 Gyr model. As the HB stars quickly turn to redder colors with increasing mass, a Red HB is always expected at younger ages (t < 10 Gyr) disregarding the morphology details at 15 Gyr.

R = Red HB (a red clump close to the RGB)

I = Intermediate HB (a skewed bell-shaped distribution peaked at Log T = 3.82 with a 3-sigma hot tail up to Log T = 4.05)

B = Blue HB (a skewed bell-shaped distribution peaked at Log T = 4.30 with a 3-sigma hot tail up to Log T = 4.60)

The second block of data summarizes the integrated Johnson colors and bolometric correction for each SSP spectrum at the given age (as labelled, in Gyr). These entries can also be found in the corresponding Set I data.

Mbol = SSP bolometric magnitude. For each model sequence, Mbol is a magnitude difference with respect to the corresponding 15 Gyr model. SSP luminosity evolution is therefore tracked consistently in bolometric assuming that Mbol = 0 at 15 Gyr. Appropriate scaling with SSP total mass and/or absolute luminosity can be done by mean of the corresponding M/L ratio from the Set I data.

(Bol-V) = Bolometric correction to the Johnson V band. For the Sun we assume (Bol-V) = -0.07 and Mbol(sun) = +4.72.

(U-V)

(B-V)

(V-R)

(V-I)

(V-J)

(V-H)

(V-K)

Note that:

tr>

1) the Johnson UBV system is reproduced according to Buser (1978, A&Ap, 62, 411).

2) Compared with the original tables in Buzzoni (1989), U magnitudes have been corrected here according to the discussion in Buzzoni (1995, ApJS, 98, 69).

3) The Cousins (V-Rc) and (V-Ic) colors can be obtained from the Johnson colors through the following transformation set of equations (Bessell 1979, PASP, 91, 589):

V-Rc = 0.73 (V-Rj) (V-Rj) <1.0

V-Rc = 0.62(V-Rj) -0.08 1.0< (V-Rj) <1.7

V-Ic = 0.713(V-Ij) (V-Ij) <0.0

V-Ic = 0.778(V-Ij) 0.0< (V-Ij)<2.0

V-Ic = 0.835(V-Ij)-0.13 2.0< (V-Ij) <3.0

4) The H filter profile is from Bessel and Brett (1988, PASP, 100, 1134), after rejecting IR-leakage longward of 2.3 μm
5) Important notice: for the Gunn and Washington magnitudes please see Set Ib

Spectral Energy Distribution (SED) of SSP models is given in the third block of data.

The big compact tables always give entries for Age = 18, 15, 12.5, 10, 8, 6, 5, 4, 3, 2 Gyr (or Age = 15, 12, 9, 6 Gyr for the case of Z = 0.1), respectively. In case a given age has not been computed, entries are set to 0.000 (this is the case, for example, of the missing 18 Gyr models for Red HB SSPs with Z > 0.01). A spectrum is a column, consisting of 342 wavelength entries for Flux(λ). Wavelength, in Å, is given in the first (left) column; it ranges from 229 to 200,000 Å with variable step.

IMPORTANT NOTICE: in order to optimize the numerical display, each SED is normalized to a total bolometric luminosity of 1E10 L_sun, and tabulated in the form of log_10 (Flux). Rescaling to absolute bolometric luminosity can be done via Mbol and the M/L ratio [see Buzzoni (1989, Sec. 6) for further details].

AB/Jun 2007

Back to the SSP models

(1)	(2)	(3)	(4)	(5)	(6)	(7)
Z	[Fe/H]	Y	s	m.loss	Minf	HB
0.0001	-2.27	0.23	2.35	0.3	0.1	R

(1):	Metallicity. We explore the range for Z = 0.0001, 0.001, 0.01, 0.017 (solar value), 0.03, and 0.1.
(2):	Iron-to-Hydrogen abundance relative to the Sun (by definition [Fe/H](sun) = 0)
(3):	Helium abundance. The value of Y is 0.23 for Z = 0.0001 and 0.001 models, Y = 0.25 for Z = 0.01, 0.017, 0.03, and Y = 0.35 for Z = 0.1. The relevant equivalence X+Y+Z = 1 holds, from which the Hydrogen abundance can be derived.
(4):	IMF power-law index. We assume dN = A M(-s) dM. For a Salpeter IMF s=2.35. In addition, the case of s = 1.35 (giant-dominated SSPs) and 3.35 (dwarf-dominated SSPs) is considered.**
(5):	Mass loss coefficient η in the Reimers (1975) formula (see Buzzoni 1989). This parameter mainly affects the AGB luminosity extension. A larger value of η means a more enhanced mass loss (that is a fainter AGB tip). The empirical tuning for low-Z SSPs indicates a typical value about 1/3 (see Iben and Renzini, 1983 ARAA, 21, 271). In our model grid we assume η = 0.3 and 0.5.
(6):	Lower mass limit for the IMF, in solar unit. Always fixed in the models at 0.1 M_sun.
(7):	Horizontal Branch morphology for the 15 Gyr model. As the HB stars quickly turn to redder colors with increasing mass, a Red HB is always expected at younger ages (t < 10 Gyr) disregarding the morphology details at 15 Gyr.
	R = Red HB (a red clump close to the RGB)
	I = Intermediate HB (a skewed bell-shaped distribution peaked at Log T = 3.82 with a 3-sigma hot tail up to Log T = 4.05)
	B = Blue HB (a skewed bell-shaped distribution peaked at Log T = 4.30 with a 3-sigma hot tail up to Log T = 4.60)

Mbol =	SSP bolometric magnitude. For each model sequence, Mbol is a magnitude difference with respect to the corresponding 15 Gyr model. SSP luminosity evolution is therefore tracked consistently in bolometric assuming that Mbol = 0 at 15 Gyr. Appropriate scaling with SSP total mass and/or absolute luminosity can be done by mean of the corresponding M/L ratio from the Set I data.
(Bol-V) =	Bolometric correction to the Johnson V band. For the Sun we assume (Bol-V) = -0.07 and Mbol(sun) = +4.72.
(U-V)
(B-V)
(V-R)
(V-I)
(V-J)
(V-H)
(V-K)