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J/ApJ/663/320       IR-through-UV extinction curve          (Fitzpatrick+, 2007)

An analysis of the shapes of interstellar extinction curves. V. The IR-through-UV curve morphology. Fitzpatrick E.L., Massa D. <Astrophys. J., 663, 320-341 (2007)> =2007ApJ...663..320F
ADC_Keywords: Models ; Extinction Keywords: dust, extinction - methods: data analysis Abstract: We study the IR-through-UV wavelength dependence of 328 Galactic interstellar extinction curves affecting normal, near-main-sequence B and late O stars. We derive the curves using a new technique that employs stellar atmosphere models in lieu of unreddened "standard" stars. Under ideal conditions, this technique is capable of virtually eliminating spectral mismatch errors in the curves. In general, it lends itself to a quantitative assessment of the errors and enables a rigorous testing of the significance of relationships between various curve parameters, regardless of whether their uncertainties are correlated. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 67 328 Basic Data for Survey Stars table3.dat 87 328 Best-Fit Parameters for Survey Stars table4.dat 138 328 Best-Fit Extinction Curve Parameters for Survey Stars refs.dat 64 83 References
Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 22 A22 --- Name Star name (1) 24- 38 A15 --- SpType MK Spectral type (2) 40- 44 F5.2 mag Vmag The V band magnitude 46- 49 I4 pc Dist ? Heliocentric distance (3) 51- 57 F7.3 deg GLON Galactic longitude 59- 64 F6.2 deg GLAT Galactic latitude 66- 67 I2 --- Ref ? Reference, in refs.dat file
Note (1): The stars are listed in order of increasing Right Ascension using the most commonly adopted forms of their names. The first preference was ``HDnnn'', followed by ``BDnnn'', etc. There are 185 survey stars which are members of open clusters or associations. The identity of the cluster or association is either contained in the star name itself (e.g., NGC 457 Pesch 34) or is given in parentheses after the star's name. Note (2): Spectral types were selected from those given in the SIMBAD database, and the source of the adopted types is shown in the "Ref". When multiple types were available for a particular star, we selected one based on our own preferred ranking of the sources. Note (3): Distances are: NGC 2244 = distance is from Perez et al. (1987PASP...99.1050P); NGC 3293 = distance is from Balona & Crampton (1974MNRAS.166..203B); Trumpler 14 and 16 = distances are from Massey & Johnson (1993, Cat. J/AJ/105/980); Cep OB3 = distance is from Crawford & Barnes (1970AJ.....75..952C). The distances to all other clusters or associations are from the Open Clusters and Galactic Structure database maintained by Wilton S. Dias, Jacques Lepine, Bruno S. Alessi, and Andre Moitinho, Cat. B/ocl, and . For the non-cluster stars, distances were calculated using the E(B-V) values from this study and the absolute magnitudes from Turner (1980ApJ...240..137T) (for mid-B and earlier types) and Blaauw 1963 (in Basic Astronomical Data, ed. K. A. Strand (Chicago: Univ. Chicago Press), chap. 20) (for mid-B and later types).
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 22 A22 --- Name Star name 24- 28 I5 K Teff Model effective temperature (2) 30- 33 I4 K e_Teff 1σ uncertainty in Teff 35- 38 F4.2 [cm/s2] log(g) Log of model surface gravity (3) 40- 43 F4.2 [cm/s2] e_log(g) 1σ uncertainty in log(g) 45- 49 F5.2 [Sun] [m/H] Log of model metallicity (4) 51- 54 F4.2 [Sun] e_[m/H] ? 1σ uncertainty in [m/H] 56- 59 F4.1 km/s Vturb Model turbulent velocity (5) 61- 63 F3.1 km/s e_Vturb ? 1σ uncertainty in Vturb 65- 70 F6.4 mas theta Model angular radius 72- 77 F6.4 mas e_theta 1σ uncertainty in theta 79- 82 F4.2 mag E(B-V) Model reddening 84- 87 F4.2 mag e_E(B-V) 1σ uncertainty in E(B-V)
Note (2): For the O stars analyzed using the TLUSTY atmosphere models, the values of Teff were adopted from the Spectral Type vs. Teff relation given in Table 2. These stars can be identified by their 1-σ uncertainties, which are ±1000K. Table 2: Adopted Temperature Scale for Main-Sequence O Stars ------------------- SpType Teff (K) ------------------- O6 40000 O6.5 38500 O7 37000 O7.5 36500 O8 36000 O8.5 34750 O9 33500 O9.5 32750 B0 32000 ------------------- Note (3): For stars in clusters, the surface gravities are determined as discussed in Sect. 3.1 and rely on stellar evolution models and cluster distance determinations. Surface gravities for non-cluster stars are not always well-determined, because of a lack of specific spectroscopic indicators. In some cases, the best-fit solutions for these stars indicated physically unlikely results (i.e., log(g)≳4.3 or log(g)≲3.0). For these stars, a value of log(g)=3.9 was assumed (which is the mean log(g) of the rest of the sample) and a 1-σ uncertainty of ±0.2 was incorporated in the error analysis. These cases can be identified by log(g) entries of "3.9±0.2". Note (4): For the O stars in the sample, our fitting procedure utilized solar abundance TLUSTY models. For these stars the values of [m/H] are indicated by entries of "0" without uncertainties. Note (5): For the O stars, the adopted TLUSTY models incorporate Vturb=10km/s. For these stars the values of Vturb are indicated by entries of "10" without uncertainties. For the B stars, which were modeled using ATLAS9 models, the values of Vturb were determined by the fitting procedure, but were constrained to lie between 0 and 10km/s. Stars whose best-fit SED models required these limiting values are indicated by Vturb entries of "0" or "10", without error bars. The uncertainties for stars with best-fit Vturb values close to these limits may be underestimated due to this truncation.
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 22 A22 --- Name Star name 24- 28 F5.3 --- x0 The UV x0 coefficient (2) 30- 34 F5.3 --- e_x0 1-σ uncertainty in x0 36- 39 F4.2 --- gamma UV γ coefficient (2) 41- 44 F4.2 --- e_gamma 1-σ uncertainty in γ 46- 50 F5.2 --- c1 UV c1 coefficient (2) 52- 55 F4.2 --- e_c1 ? 1-σ uncertainty in c1 57- 61 F5.2 --- c2 UV c2 coefficient (2) 63- 66 F4.2 --- e_c2 1-σ uncertainty in c2 68- 72 F5.2 --- c3 UV c3 coefficient (2) 74- 77 F4.2 --- e_c3 1-σ uncertainty in c3 79- 82 F4.2 --- c4 UV c4 coefficient (2) 84- 87 F4.2 --- e_c4 1-σ uncertainty in c4 89- 92 F4.2 --- c5 UV c5 coefficient (2) 94- 97 F4.2 --- e_c5 1-σ uncertainty in c5 99-102 F4.2 --- O1 ? Optical spline O1 point (3) 104-107 F4.2 --- e_O1 ? 1-σ uncertainty in O1 109-112 F4.2 --- O2 Optical spline O2 point (3) 114-118 F5.2 --- O3 Optical spline O3 point (3) 120-123 F4.2 --- R(V) IR R(V) coefficient (4) 125-128 F4.2 --- e_R(V) ? 1-σ uncertainty in R(V) 130-133 F4.2 --- kIR IR kIR coefficient (4) 135-138 F4.2 --- e_kIR ? 1-σ uncertainty in kIR
Note (2): Extinction curve is defined by k(λ-V) = c1+c2x+c3.D(x,x0,γ) for x≤c5 and = c1+c2x+c3.D(x,x0,γ) = c4(x-c5)2 for x>c5. where x=λ-1, in units of inverse microns (um-1) and D(x,x0,γ)=x2/[(x2-x02)+x2γ2] For the stars HD237019, HD18352, and HD25443 the long wavelength IUE spectra are incomplete. For these cases we constrained the UV linear extinction component to follow the relation c1=2.18-2.91*c2 from Fitzpatrick (2004, in ASP Conf. Ser. 309, 33). For these stars we list uncertainties for the c2 values but not for the c1 values. Note (3): The uncertainties in the O2 and O3 optical spline points (at wavelengths of 4000 and 5530 Angstroms, respectively) are typically 0.01 or less and are not listed. For several stars, those without U band photometry, we did not solve for the O1 point at 3300 Angstroms. Note (4): R(V) is the ratio of reddening to extinction at V. For field stars without IR photometry, we assumed R(V)=3.1 and kIR=1.11, with the latter based on the relation kIR=0.63*R(V)-0.84 from Fitzpatrick (2004, in ASP Conf. Ser. 309, 33) clusters, we adopted the mean R(V) of the other cluster members and a value of kIR based on the aforementioned relation. These assumed values are listed in the Table without uncertainties. Several survey stars have apparently noisy JHK data and yielded very uncertain values of kIR. For these, we ultimately derived the extinction curve by solving for the best-fit value of R(V) with kIR constrained to follow the Fitzpatrick (2004, in ASP Conf. Ser. 309, 33) relation. The resultant R(V) values are listed with their uncertainties while the kIR values are listed without uncertainties.
Byte-by-byte Description of file: refs.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Ref Reference number 4- 22 A19 --- BibCode BibCode 24- 45 A22 --- Aut Author's name 46- 64 A19 --- Com Comments
History: From electronic version of the journal References: Fitzpatrick & Massa, Paper I 1986ApJ...307..286F Fitzpatrick & Massa, Paper II 1988ApJ...328..734F Fitzpatrick & Massa, Paper III 1990ApJS...72..163F Fitzpatrick & Massa, Paper IV 2005AJ....130.1127F Fitzpatrick & Massa, Paper VI 2009ApJ...699.1209F
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 14-Aug-2009
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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