J/A+AS/109/293 Heterochromatic extinction. I. (Grebel+, 1995)
Heterochromatic extinction. I. Dependence of interstellar extinction on stellar
temperature, surface gravity, and metallicity.
GREBEL E.K., ROBERTS W.J.
<Astron. Astrophys. Suppl. Ser. 109, 293 (1995)>
=1995A&AS..109..293G 1995A&AS..109..293G (SIMBAD/NED Reference)
ADC_Keywords: Extinction; Interstellar medium; Stars, atmospheres
Keywords: ISM: dust, extinction - techniques: photometric -
stars: fundamental parameters
File Summary:
--------------------------------------------------------------------------------
File Name Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
coeff1 64 168 *Rational polynomial coefficients
coeff2 215 168 *Actual coefficients
diffb 139 638 Differential interstellar extinction in UBVRI
diffw 114 638 Differential interstellar extinction in CMT1T2
totb 95 638 Total interstellar extinction in UBVRI
totw 75 638 Total interstellar extinction in CMT1T2
--------------------------------------------------------------------------------
Note on tables coeff1, coeff2:
These tables show the coefficients of fits purely linear in
temperature colour to the interstellar extinctions for all passbands
considered. The lowest temperature model, 3500K, was excluded from ALL
fits to B-V, because it badly behaved there. The same temperature was
also excluded from the fits to V-I and M-T2 for [Fe/H]=-2.0, because
these temperature colours are not monotonic there.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: totb
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- Star Star type (1)
4- 7 F4.1 Sun [Fe/H] Metallicity
10- 15 F6.0 K Teff Effective temperature
19- 25 F7.5 mag A(U)X Total interstellar extinction in U for airmass 1
(because U filter is defined by atmospheric
cutoff)
29- 35 F7.5 mag A(B)X Total interstellar extinction in B for airmass 1
(to allow calculation of U-B.)
39- 45 F7.5 mag A(B) Total interstellar extinction in B for airmass 0
49- 55 F7.5 mag A(V) Total interstellar extinction in V for airmass 0
59- 65 F7.5 mag A(R) Total interstellar extinction in R for airmass 0
69- 75 F7.5 mag A(I) Total interstellar extinction in I for airmass 0
79- 85 F7.5 --- R(V) Ratio of total to differential extinction
89- 95 F7.5 --- R(V)/R(V0) R(V0): same ratio as R(V) but for star with
standard spectrum,
i.e. T_eff=17000, log(g)=5.0, and [Fe/H]=0.
--------------------------------------------------------------------------------
Note (1): MS = Main Sequence,
RG = Red Giants (log(g)=2.5),
SG = SuperGiants (i.e., the lowest surface gravity for that
temperature in the Kurucz model family).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: diffb
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- Star Star type (1)
4- 7 F4.1 Sun [Fe/H] Metallicity
9- 14 F6.0 K Teff effective temperature
17- 23 F7.4 mag U-B (U-B) colour index
26- 31 F6.4 mag E(U-B) differential interstellar extinction in (U-B)
34- 39 F6.4 --- R1 E(U-B)/E(B-V) ratio
42- 48 F7.4 mag B-V (B-V) colour index
51- 56 F6.4 mag E(B-V) differential interstellar extinction in (B-V)
59- 64 F6.4 --- R2 E(B-V)/E(B-V) ratio
67- 73 F7.4 mag V-R (V-R) colour index
76- 81 F6.4 mag E(V-R) differential interstellar extinction in (V-R)
84- 89 F6.4 --- R3 E(V-R)/E(B-V) ratio
92- 98 F7.4 mag R-I (R-I) colour index
101-106 F6.4 mag E(R-I) differential interstellar extinction in (R-I)
109-114 F6.4 --- R4 E(R-I)/E(B-V) ratio
117-123 F7.4 mag V-I (V-I) colour index
126-131 F6.4 mag E(V-I) differential interstellar extinction in (V-I)
134-139 F6.4 --- R5 E(V-I)/E(B-V) ratio
--------------------------------------------------------------------------------
Note (1): MS = Main Sequence,
RG = Red Giants (log(g)=2.5),
SG = SuperGiants (i.e., the lowest surface gravity for that
temperature in the Kurucz model family).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: totw
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- Star Star type (1)
4- 7 F4.1 Sun [Fe/H] Metallicity
10- 15 F6.0 K Teff Effective temperature
19- 25 F7.5 mag A(C) Total interstellar extinction in C for airmass 0
29- 35 F7.5 mag A(M) Total interstellar extinction in M for airmass 0
39- 45 F7.5 mag A(T1) Total interstellar extinction in T1 for airmass 0
49- 55 F7.5 mag A(T2) Total interstellar extinction in T2 for airmass 0
59- 65 F7.5 --- R(T2) Ratio of total to differential extinction
69- 75 F7.5 --- R(T2)/R(V0) R(V0): same ratio as R(T2) but for star with
standard spectrum,
i.e. T_eff=17000, log(g)=5.0, and [Fe/H]=0.0
--------------------------------------------------------------------------------
Note (1): MS = Main Sequence,
RG = Red Giants (log(g)=2.5),
SG = SuperGiants (i.e., the lowest surface gravity for that
temperature in the Kurucz model family).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: diffw
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- Star Star type (1)
4- 7 F4.1 Sun [Fe/H] Metallicity
9- 14 F6.0 K Teff effective temperature
17- 23 F7.4 mag C-M (C-M) colour index
26- 31 F6.4 mag E(C-M) differential interstellar extinction in (C-M)
34- 39 F6.4 --- R1 E(C-M)/E(M-T2) ratio
42- 48 F7.4 mag M-T1 (M-T1) colour index
51- 56 F6.4 mag E(M-T1) differential interstellar extinction in (M-T1)
59- 64 F6.4 --- R2 E(M-T1)/E(M-T2) ratio
67- 73 F7.4 mag T1-T2 (T1-T2) colour index
76- 81 F6.4 mag E(T1-T2) differential interstellar extinction in (T1-T2)
84- 89 F6.4 --- R3 E(T1-T2)/E(M-T2) ratio
92- 98 F7.4 mag M-T2 (M-T2) colour index
101-106 F6.4 mag E(M-T2) differential interstellar extinction in (M-T2)
109-114 F6.4 --- R4 E(M-T2)/E(M-T2) ratio
--------------------------------------------------------------------------------
Note (1): MS = Main Sequence,
RG = Red Giants (log(g)=2.5),
SG = SuperGiants (i.e., the lowest surface gravity for that
temperature in the Kurucz model family).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: coeff1
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- Filter Filters or quantity involved (1)
4- 8 A5 --- Band Quantity, e.g., filter or colour
12- 14 F3.1 [cm/s2] logg []? Surface gravity
15 A1 --- n_logg [m ] Lowest surface gravity model when there
is no value for logg (2)
19- 22 F4.1 [Sun] [Fe/H] Metallicity
27 I1 --- num Numerator degree (3)
33 I1 --- den Denominator degree (3)
40- 49 E10.4 --- MaxDev Largest deviation (4)
52- 57 F6.3 --- TCmin Lower boundary of the valid range of
temperature colour for that fit (5)
60- 64 F5.3 --- TCmax Upper boundary of the valid range of
temperature colour for that fit (5)
--------------------------------------------------------------------------------
Note (1): UB = U, U-B
BR = B, B-R
BV = V, B-V
VI = V-I
RV = R_V = A_V/E(B-V)
CM = C, C-M
M1 = M, M-T1
M2 = M-T2
R2 = R-T2
Note (2): 'm' means the lowest surface gravity model for that temperature in the
Kurucz models, i.e., the SG=supergiants
Note (3): Degree of the numerator and the denominator of the best fitting
rational polynomial found (in some cases a linear fit was chosen
without searching for a higher order fit). The numerator always stars
with a_0, so there is one more coefficient in the numerator than the
degree. The denominator starts with b_1.
Note (4): Largest deviation in extinction of the rational polynomial from any
of the data points in the interstellar extinction table (dif* and
tot*) for that fit, as returned by the Numerical Recipes routine
'ratlsq'.
Note (5): For the ISM the TCs are B-V and M-T2.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: coeff2
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Band Quantity, e.g., filter or colour
10- 12 F3.1 [cm/s2] logg []? Surface gravity
13 A1 --- n_logg [m ] Lowest surface gravity model when there
is no value for logg (1)
17- 20 F4.1 [Sun] [Fe/H] Metallicity
22- 32 E11.4 --- a0 Coefficient a0 in the numerator
34- 44 E11.4 --- a1 Coefficient a1 in the numerator
46- 56 E11.4 --- a2 []? Coefficient a2 in the numerator
58- 68 E11.4 --- a3 []? Coefficient a3 in the numerator
70- 80 E11.4 --- a4 []? Coefficient a4 in the numerator
82- 92 E11.4 --- a5 []? Coefficient a5 in the numerator
94-104 E11.4 --- a6 []? Coefficient a6 in the numerator
106-116 E11.4 --- a7 []? Coefficient a7 in the numerator
118-128 E11.4 --- a8 []? Coefficient a8 in the numerator
133-143 E11.4 --- b1 []? Coefficient b1 in the denominator
145-155 E11.4 --- b2 []? Coefficient b2 in the denominator
157-167 E11.4 --- b3 []? Coefficient b3 in the denominator
169-179 E11.4 --- b4 []? Coefficient b4 in the denominator
181-191 E11.4 --- b5 []? Coefficient b5 in the denominator
193-203 E11.4 --- b6 []? Coefficient b6 in the denominator
205-215 E11.4 --- b7 []? Coefficient b7 in the denominator
--------------------------------------------------------------------------------
Note (1): 'm' means the lowest surface gravity model for that temperature in the
Kurucz models, i.e., the SG=supergiants
--------------------------------------------------------------------------------
(End) Patricia Bauer [CDS] 07-Sep-1994