Spectrophotometric Standards
MODS Primary Spectrophotometry Standards
10- and 50-Angstrom Flux Tables
For each primary standard star, flux tables with 10Å bin widths are provided. These tables are in IRAF-style ASCII 3-column format ready to be used with IRAF. Where necessary, HST stellar models or other HST calibration data were used to extend the near-IR wavelength coverage to 10500Å. These are suitable for grating-mode calibrations.
Tables with 50Å-bin widths are better suited for prism-mode calibrations and these are also provided for most of the stars. The fluxes are based on CALSPEC and the Spec50 flux tables Massey et al (1988, ApJ 328, 315), with extensions to 1 micron from Massey and Gronwall (1990, ApJ 358, 344)
These tables have the major telluric absorption complexes censored, and the brighter stellar absorption lines have been cut out in most (but not all) tables.
The original, uncensored flux tables are available from the HST CALSPEC database.
Note that the modsIDL Reduction Pipeline uses the full CALSPEC flux tables which are included in the software distribution.
Data on the MODS Primary Spectrophotometric Standards
Star |
RA
(J2000)
|
Dec
(J2000)
|
Sp Type |
m(5556)
(mag)
|
pmRA
(mas/yr)
|
pmDec
(mas/yr)
|
t[Grating]
(sec)
|
t[Prism]
(sec)
|
Downloads |
---|---|---|---|---|---|---|---|---|---|
G191-B2B [1] | 05:05:30.613 | +52:49:51.96 | DA0 | 11.85 | +7.45 | -89.54 | 90 | 10 | Finder Chart 10Å Flux Table 50Å Flux Table |
GD71 [2] | 05:52:27.614 | +15:53:13.75 | DA1 | 13.03 | +85 | -174 | 180 | 30 | Finder Chart 10Å Flux Table 50Å Flux Table |
Feige 34 | 10:39:36.740 | +43:06:09.26 | sdO | 11.25 | +14.09 | -25.01 | 120 | 15 | Finder Chart 10Å Flux Table 50Å Flux Table |
Feige 66 [3] | 12:37:23.517 | +25:03:59.88 | sdO | 10.54 | +3.01 | -26.05 | 120 | 15 | Finder Chart 10Å Flux Table 50Å Flux Table |
Feige 67 | 12:41:51.791 | +17:31:19.76 | sdO | 11.89 | -6.15 | -36.27 | 120 | 15 | Finder Chart 10Å Flux Table 50Å Flux Table |
GD 153 [4] | 12:57:02.337 | +22:01:52:68 | DA1 | 13.35 | -46 | -204 | 180 | 30 | Finder Chart 10Å Flux Table |
Hz 43 [5] | 13:16:21.853 | +29:05:55.38 | DA1 | 12.91 | -157.96 | -110.23 | 180 | 30 | Finder Chart 10Å Flux Table |
Hz 44 | 13:23:35.258 | +36:07:59.51 | sdO | 11.47 | -61.6 | -3.1 | 120 | 15 | Finder Chart 10Å Flux Table 50Å Flux Table |
BD+33 2642 | 15:51:59.886 | +32:56:54.33 | B2IV | 10.80 | -13.57 | +0.72 | 120 | 15 | Finder Chart 10Å Flux Table |
BD+28 4211 [6] | 21:51:11.021 | +28:51:50.36 | sdOp | 10.56 | -35.55 | -58.74 | 60 | 10 | Finder Chart 10Å Flux Table 50Å Flux Table |
Feige 110 | 23:19:58.398 | -05:09:56.16 | sdO | 11.88 | -10.68 | +0.31 | 90 | 10 | Finder Chart 10Å Flux Table 50Å Flux Table |
[1] – G191-B2B is an HST primary white dwarf star. On the finder chart it is the northernmost of the two bright stars in the field.
[2] – GD71 is an HST primary white dwarf standard stars. The NIR extension is based on HST model spectrum.
[3] – Feige 66 has only relatively low-quality near-IR extension data, and should only be used in the blue or out to about 9200Å.
[4] – GD153 is an HST primary white dwarf star. The NIR extension is based on the HST fluxes shifted by -0.02mag.
[5] – Hz 43 is an HST primary white dwarf star. The NIR extension is based on the HST model spectrum. A faint binary M-dwarf companion, Hz43B (V=14.3), is located 3-arcsec away, so this star is not recommended during poor seeing.
[6] – BD+28 4211 has a faint red companion 2.8-arcsec away, and is only recommended for use in the blue channel in good seeing.
A model extinction curve for LBT
Table 2: LBT Model Extinction Curve
λ (Å) | Kλ [mag/airmass] |
3200 | 0.866 |
3500 | 0.511 |
4000 | 0.311 |
4500 | 0.207 |
5000 | 0.153 |
5500 | 0.128 |
6000 | 0.113 |
6450 | 0.088 |
6500 | 0.085 |
7000 | 0.063 |
7500 | 0.053 |
8000 | 0.044 |
8210 | 0.043 |
8260 | 0.042 |
8370 | 0.041 |
8708 | 0.026 |
10256 | 0.020 |