Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.stsci.edu/~INS/2010CalWorkshop/pickles.pdf Äàòà èçìåíåíèÿ: Mon Apr 23 22:58:47 2012 Äàòà èíäåêñèðîâàíèÿ: Sat Mar 1 14:27:38 2014 Êîäèðîâêà: Ïîèñêîâûå ñëîâà: ic 2118

The 2010 STScI Calibration Workshop Space Telescope Science Institute, 2010 Susana Deustua and Cristina Oliveira, eds.

UBVRI-ZY and ugriz zeropoints from 20 calspec standards
Andrew Pickles Las Cumbres Observatory Global Telescope, Santa Barbara, CA Abstract. Synthesized UBVRI-ZY and ugriz zerop oints are presented, calibrated on 20 calsp ec standards with standard photometry and covering a wide range of color, from DA white dwarfs through G/K stars to VB8 (M7V). The zerop oint dispersions are 0.027, 0.020, 0.008, 0.014 and 0.016 mag respectively in UBVRI, where the UM BM VC RC IC filter system profiles minimize these disp ersions. V(Vega) is found to b e 0.021 ± 0.008 mag from an average of 17 calsp ec standards, with Vega colors which are close to zero. Zerop oints for u & u' are found to b e -0.03 ± 0.02 mag; those for griz and g'r'i'z' are 0.00 ± 0.02 mag.

1.

Filters and zerop oints based on sp ectrophotometric standards

Mean fluxes and synthetic magnitudes in the system bandpasses of all the filters have b een computed for up to 20 standards which have b oth accurate digital sp ectra available from calspec1 , and measured photometry from the literature. The filter-bands discussed here are illustrated in figure 1. Synthesized magnitudes of flux calibrated sp ectra have b een determined using these filter system bandpasses and the procedures describ ed in the Synphot User's Guide2 mag (b) = mag (b) - 5 log10
pivot

+18.692 - Zer oP oint

b

(1)

where the numeric constant, as derived in Sirianni et al (2005), has the advantage of bringing mag close to the AB79 system of Oke & Gunn (1983). The bandpass zerop oints are to b e determined. The approach is similar to that presented by Holb erg & Bergeron (2006) but delib erately attempts to calibrate a large numb er of filters with standards covering a wide range of color and sp ectral typ e. The small zerop oint disp ersions achieved here demonstrate the validity of this approach over a wide variety of sp ectral typ es and colors. They reinforce the advances that have b een made in accurate flux calibration by Bohlin (1996), Colina & Bohlin (1997), Bohlin et al (2001), & Bohlin (2010). 2. Calsp ec standards

There are 13 standards with catalog photometry and STIS NIC 003 calibrated sp ectrophotometry covering 0.1 to 2.5 µ, which include the latest HST calspec calibration enhancements and the 2010 corrections to STIS gain settings. The sp ectra are mainly of white dwarfs, but include four G dwarfs and VB8(=LHS 429, a late M dwarf ) so provide significant color range: -0.3 < V - I < 4.6.
1 2

http://www.stsci.edu/hst/observatory/cdbs/calspec.html http://www.stsci.edu/resources/software hardware/stsdas/synphot

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Figure 1: The filter system bandpasses discussed here are illustrated. In the first panel the Tycho2 BT VT filter system transmissions are taken from Maiz Ap ell´niz (2006), and overa plotted (dotted lines) in the third panel for convenient reference. The 2MASS J2 H2 K2/S system total resp onse curves are from the IPAC website; the JH KMK O filter transmission curves (dotted) are from Tokunaga et al (2002). In the second panel the Landolt UL BL VL RL IL transmission curves for the filters alone are shown (dotted, Landolt 1992a); their normalized system resp onse including typical atmosphere and detector QE are shown (solid, Cohen 2003a). In the third panel the synthetic UM BM VM filters are from Maiz Ap ell´niz (2006) (VM plotted as dashed line); the VC RC IC synthetic curves are from Bessell a (1979) and the ZV YV curves are from the UKIRT/VISTA collab oration. An Rp "Mouldtyp e" R-system resp onse is also illustrated. In the b ottom panel the Sloan system bandpasses are shown for b oth the unprimed survey imaging bandpasses (dotted lines, where the filter interference red edges move bluer in the vacuum of the survey camera) and primed bandpasses used in air for PT and Southern standard observations (u'g'r'i'z' ­ solid lines); they are from the JHU skyservice and the USNO FNAL websites.


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Figure 2: The bandpasses, Vega magnitudes (colored symbols) and ±2 zeropoint dispersions (bars) from table 1 are over-plotted on the STIS 005 calspec/Kurucz spectrum of Vega, which defines the nominal 0-mag definition for filters on the vega system. The horizontal line at 3.631 10-20 erg cm-2 sec-1 Hz -1 (3631 Jy) illustrates the AB=0 mag reference. There are two calspec K giants (KF08T3, KF06T1) with low reddening which were observed with NICMOS to provide IRAC calibration (Reach et al 2005). There is little optical standard photometry for these two K giants, so they are only included in the 2MASS JH K2/S zerop oint averages, but optical colors estimated from their typ es are shown to b e consistent with the derived optical zerop oints. There are three additional calspec white dwarfs with coverage to 1µ (G93-48, GD 50, Feige 34), and two sub dwarfs (G158-100, BD +26 2606) observed by Oke (1990) and Oke & Gunn (1983) for which fairly extensive photometric data are available in the literature. The latter 5 sp ectra calibrated from the uv to 1µ, were extended to 2.5µ for illustrative purp oses. Their synthetic infrared magnitudes are computed and shown for comparison, but only their optical zerop oints are combined in the averages. 2.1. Standard Catalog Magnitudes

The matching "catalog" photometry for calspec standards comes from i) the Tycho2 catalog for BT VT (HÜg et al 2000), ii) the 2MASS catalog for J2 H2 K2/S (Cutri 1998), iii) UB V RI data for GD 71 (DA1), G93-48 (DA3) & GD 50 (DA2) from Landolt (2009), and for G191B2B (DA0), BD +17 4708 (sdF8), BD +26 2606 (sdF), AGK +81 266 (sdO), GRW +70 5824 (DA3), LDS 749B (DBQ4), Feige 110 (DOp), Feige 34 (DA) & G158-100 (sdG) from Landolt & Uomoto (2007), iv) from Bessell (1991) for optical and infrared photometry of VB8 (M7 V), v) from the UKIRT standards listed on the JAC/UKIRT website3 for JH KMK O and their WFCAM ZV YV data, and vi) from Wegner (1983), Lacomb & Fontaine (1981) and

3

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Hauck & Mermilliod (1998) for Stromgren standards (white dwarfs). The ab ove photometric data is on the "Vega" system where the magnitudes of Vega are nominally zero in all bands. Sloan catalog (vii) data on the AB system are from Smith et al (2002) for primary standards, from the SDSS PT catalog Davenp ort et al (2007) and Southern SDSS standards Smith et al (2005), from the SDSS DR7 database4 for LDS 749B, VB8, GD 50, and in 2 cases (G191-B2B & GD 71) from Holb erg & Bergeron (2006) for u g r i z magnitudes. Additional UB V RI and ugr iz photometric data for GD 153 (DA0) are from Holb erg & Bergeron (2006). Additional BV data for P041C, P177D, P330E (G0 V), KF08T3 (K0.5 I I I) and KF06T1 (K1.5 I I I) are from the calspec website. For each standard and each filter, magnitudes have b een computed via equation 1, and the zerop oints calculated to match synthetic to observed magnitudes. 3. Zerop oint means and disp ersions

Complete tables are presented in Pickles & Depagne (2010). Table 1 summarizes the derived zerop oint means and disp ersions for each filter, adopted zerop oints, synthesized magnitudes and fluxes of the STIS 005 calspec/Kurucz sp ectrum of Vega, and derived values of < F ( ) > for 0-magnitude in all filters. The numb er of standards included in each filter zerop oint calculation ranges from 5 for VT to 17 for B and V . The filter bands and derived magnitudes and zero-p oint disp ersions for Vega from table 1 are illustrated in figure 2, where the STIS 005 calspec sp ectrum illustrates the nominal 0mag definition for filters on the vega system, and the horizontal line at 3631 Jy illustrates the AB=0 mag reference. The error bars show the synthesized magnitudes with ±2 zerop oint disp ersion errors. The 2MASS and SDSS coordinates of VB8 differ by 7.4-arcsec, corresp onding to the large prop er motion (-0.77, -0.87 arcsec/year) for VB8 b etween the ep ochs of the two surveys. Good VB8 zerop oint fits are obtained for BV RI , J2 H2 K2/S and HKMK O and gr z , but not for JMK O , u or i bands. There is no U-band photometry for VB8. 4. Choice of Landolt synthetic filter bandpasses

Several p ossible synthetic system bandpass profiles were tested for UB V RI , and an empirical choice made of the b est system bandpass(es) that minimize zerop oint scatter in the fitted mean zerop oints for each filter, over the full color range. Table 1 lists zerop oints for UB V RI using b oth Landolt (system) filter resp onse functions convolved with a typical atmosphere and detector resp onse Cohen et al (2003a), and synthetic system bandpasses for UM BM VM from Maiz Ap ell´niz (2006) and VC RC IC from a Bessell (1979). It may seem that the Landolt system resp onse curves would provide the optimum synthetic matches to Landolt photometry, but this is not the case, as shown by the results in table 1. Both Landolt and Kron-Cousins measurements seek to emulate the original Johnson system for UBV. Both apply color-calibrations to their instrumental magnitudes, to bring them into corresp ondence with catalog values extending back several decades. These steps are summarized in Landolt (2007) for example, and previously in Landolt (1983, 1992a, 1992b) to illustrate how equipment changes over time have required slightly different color corrections to maintain integrity with the original system definition. These calibration steps are further reviewed in Sung & Bessell (2000).

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Figure 3: Zerop oints are shown for UL BL VL RL IL (left) and UM BM VC RC IC (right) as a function of standard V - I color. Vertical error bars indicate the average and ±1 disp ersion in each panel. Crosses indicate White Dwarfs, Pentagons indicate dwarfs. Three p oint stars indicate the two K giants, which are shown but not included in these zerop oint averages or disp ersion as they lack accurate UBVRI photometry. The reddest p oint corresp onding to the M7 V VB8 lacks U-band data. The selected UBVRI system profiles on the right minimize zerop oint scatter and trend with color.

It is p ossible to measure synthetic magnitudes in the Landolt bandpasses and apply corrections to achieve "standard" values. But it is clearly preferable to find the synthetic bandpasses that b est match the sp ectrophotometric data with zerop oints, and no color term(s). For UBVRI, the results in table 1 and figure 3 indicate that these are b est provided by the UM BM VC RC IC bandpasses. In figure 3 and subsequently, the ordinate scale is set so that vertically higher zerop oints result in magnitudes which are larger (fainter). The zerop oint disp ersions are 0.027, 0.020, 0.008, 0.014 and0.016 mag for UM BM VC RC IC resp ectively in table 1, for the full color range from White Dwarfs to VB8 (-0.3 < V - I < 4.6). The effective wavelengths vary from 355 to 371 nm, 432 to 472nm, 544 to 558 nm, 640 to 738 nm and 785 to 805 nm for UM BM VC RC IC resp ectively, b etween White Dwarfs and VB8. Figure 3 illustrates that the selected bands show much less zerop oint disp ersion than do UL BL VL RL IL , with negligible trend with color. This is not a criticism of Landolt system resp onse curves, which enable accurate photometry with appropriate calibration and color corrections, but indicates that the selected UM BM VC RC IC system profiles are b est for deriving synthetic sp ectrophotometry of flux calibrated sp ectra to prop erly match Landolt photometry. The zerop oint disp ersions for U3 B3 from Azusienis & Straizys (1969) and Buser (1978) in table 1 are worse, at 0.050 and 0.024 mag resp ectively, and thus supp ort the "inflected" UM transmission curve as a b etter U-band measure for stars of varying typ e & color. The disp ersion for VM is marginally worse than for VC , where VC has a slightly more elongated red tail than VM . The zerop oint disp ersions for UB V RI and ugr iz (primed and unprimed) in table 1, typically closer to 0.02 mag than 0.01 mag, indicate b oth the accuracy and the current limitations of comparing synthetic photometry of well calibrated sp ectra with good standard photometry. Tighter fits can b e obtained by restricting the selection of comparison stars,


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Figure 4: Zerop oints are shown for BT VT (left ordinate) and ZV YV (right) as a function of standard V - I color, with averages and disp ersions as vertical bars. The YV zerop oint for G158-100 is shown in parentheses but not included in the average. Symb ols as b efore. for instance to only WD standards. But such zerop oints are then a function of color, and lead to errors for other stellar typ es much larger than the nominal disp ersion. It is gratifying that these comparisons match so well over a large range of color and standard typ es, confirming the increasing corresp ondence of sp ectrophotometric to photometric standards, and setting the basis for accurately calibrated magnitudes of an extended library of synthetic sp ectra. 4.1. Other synthetic filter zerop oints on the Vega system

The transmission functions for BT VT have b een taken from Maiz Ap ell´niz (2006). The a zerop oint disp ersions for BT VT are 0.045 and 0.020 mag resp ectively, which is acceptable given the typical errors in the photometric values for fainter stars, and for several standards included here. There are a total of 7 values covering a color range from white dwarfs to G dwarfs for BT , but only 5 with accurate VT information, with HD209458 (G0 V ­ out of planet occultation) b eing the reddest comparison standard for BT VT . The filter transmission functions for ZV YV have b een taken from the Vista website5 , where the subscript "V" is used to refer to b oth the VISTA/UKIDSS consortium and the fact that these are vega based magnitudes. The WFCAM detector QE is not included but, unlike a CCD, is roughly flat over these wavelengths. The disp ersions for ZV YV zerop oints, compared to only 5 and 4 UKIRT standards measured with the WFCAM filters, are 0.038 and 0.031 mag resp ectively. The YV zerop oint for G158-100 is susp ect as its sp ectrum is not well defined at 1µ. ZV YV zerop oint determinations may improve as more photometric standards in common with sp ectrophotometric standards are measured. The zerop oint results and color ranges for BT VT ZV YV are illustrated in figure 4. The transmission functions of the 2MASS filters, including detector and typical atmosphere, have b een taken from the IPAC website6 . The zerop oint disp ersions for J2 H2 K2/S ,
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http://www.vista.ac.uk/Files/filters http://www.ipac.caltech.edu/2mass/overview/about2mass.html


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Figure 5: Zerop oints are shown for J2 H2 K2/S (left) and JH KMK O (right) as a function of standard V - I color, with averages and disp ersions. Symb ols as b efore. The K I I I p oints (triangles) have b een included for JH K2/S The zerop oints for JH KMK O show some trend with color, but the JMK O value for VB8 has b een excluded due to uncertainty over its catalog magnitude. indicated graphically in figure 5, are ab out 0.02 mag, corresponding to the typical (low) 2MASS errors for these stars. The transmission functions for the JHK filters on the Mauna Kea Observatory (MKO) system have b een taken from Tokunaga, Simons & Vacca (2002). The zerop oint disp ersions for JH KMK O are 0.02, 0.02 & 0.04 mag resp ectively, for relatively few standards, and they do show trends with color. The JMK O zerop oint for VB8 is indicated in figure 5 but, due to uncertainty with its catalog magnitude, it is not included in the JMK O zerop oint average. The transmission functions for the Stromgren filters (not illustrated) are from Maiz Ap ell´niz (2006). The zerop oints derived in table 1 are -0.290 ± 0.035, -0.316 ± 0.012, a -0.181 ± 0.024 and -0.041 ± 0.030 for Stromgren uv by resp ectively. These are averaged over 7 calspec white dwarfs for which Stromgren photometry was found in the literature. The Stromgren zerop oints listed in table 1 lead to Vega magnitudes of 1.431, 0.189, 0.029 and 0.046 in Stromgren uv by resp ectively, compared to values of 1.432, 0.179, 0.018 and 0.014 derived in Maiz Ap ell´ iz (2007). an 5. Sloan filters on the AB system

The transmission functions of the unprimed ugr iz filters used in the imaging camera, including typical atmosphere and detector resp onse, have b een taken from the skyservice website7 at Johns Hopkins University (JHU). Those for the primed u g r i z filters used for standard observations have b een taken from the United States Naval Observatory (USNO) website8 , for 1.3 airmasses. The SDSS survey u-band data for VB8 app ears to b e too bright, likely b ecause of the known red leak. The DR7 i-band magnitude is close to the r-band magnitude, and app ears too faint for such a red star. The u and i band data for VB8 has b een omitted from the zerop oint averages.
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http://skyservice.pha.jhu.edu http://www-star.fnal.gov/ugriz/Filters/response.html


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Figure 6: Zerop oints are shown for u g r i z and ugr iz as a function of standard V - I color, with averages and disp ersions. VB8 is present in the gr z plots, but has b een omitted in the ui plots. The K I I I p oints are missing as there are no ugr iz data for them. Symb ols as b efore. In order to compute zerop oints for the imaging survey (unprimed) Sloan bandpasses ugr iz , conversion relations b etween the primed and unprimed Sloan system values were computed by comparing synthetic magnitudes of digital library sp ectra from Pickles (1998). With the exception of two zerop oint adjustments for g and r , these relations are identical to those listed on the SDSS site9 , and are summarized here. u= u ( = 0.011) g = 0.037 + g +0.060 (g - r - 0.53) ( = 0.012) r = 0.010 + r +0.035 (r - i - 0.21) ( = 0.007) i= i +0.041 (r - i - 0.21) ( = 0.015) z= z ( = 0.003) These relations were used to convert SDSS standard values on the primed system to unprimed values (and vice versa when only DR7 data was available, eg. for for LDS 749B, P177D, P330E & GD 50), then compared with synthetic magnitudes computed in the unprimed bandpasses to derive their zerop oints and disp ersions. The zerop oint disp ersions for u g r i z and ugr iz listed in table 1 are all ab out 0.02 mag, for up to 14 standards covering a wide color range. There is little evidence for non-zero zerop oints in griz; they are zero to within the measured disp ersions, and are adopted zero in table 1. Zerop oints for b oth u and u are -0.03 ± 0.02 mag. The zerop oint results for u g r i z and ugr iz are illustrated in figure 6.

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http://www.sdss.org/dr5/algorithms/jeg photometric eq dr1.html


634 6.

Pickles V-band magnitude of Vega

The VC zerop oint derivation here, based on 17 standards (including VB8), results in a Landolt V magnitude of VC = 0.021 ± 0.008 for the STIS 005 calspec sp ectrum of Vega, with colors of U-B = -0.007 ± 0.031, B-V = -0.009 ± 0.022, V-R = -0.002 ± 0.016 and V-I = 0.010 ± 0.018. These values, based on 13­17 standards, are within quoted errors of those derived in Maiz Ap ell´niz (2007). a Note that using the Cohen et al (2003a) filter definition results in a zerop oint using all 17 standards which leads to VL (Vega) = 0.013 ± 0.021, or alternatively VL (Vega) = 0.024 ± 0.002 when using a zerop oint based solely on the bluest three DA white dwarfs. The latter value is close to the recently adopted value of Landolt V (Vega) = 0.025 mag. However the VL zerop oint is clearly a function of color, as seen in figure 3. For the appropriate V-I = -0.01 color for Vega, the color-corrected zerop oint (ZPVL = -0.022), leads to VL (Vega) = 0.021, ie. the same as the VC (Vega) derivation ab ove -- when color effects are taken into account. We argue that our VC (Vega) magnitude of 0.021 ± 0.008 represents a realistic mean value and error for the Landolt V magnitude of the STIS 005 sp ectrum of Vega. The zerop oint disp ersion can probably b e improved by standard photometric measurements of more red sp ectrophotometric standards, including the IRAC K giants, which are shown in figure 3 but not used, as they lack optical standard photometry. The further question of the small differences b etween Landolt, Kron-Cousins (SAAO) and Johnson V magnitudes are discussed in Landolt (1983, 1992a) and Menzies et al (1991) and summarized again in Sung & Bessell (2000), but is sidestepp ed here. Here we compare UB V RI synthetic sp ectrophotometry of calspec standards to available published photometry on the Landolt system. 7. Vega and Zero magnitude fluxes

The final column of table 1 show the fluxes measured on the STIS 005 sp ectrum of Vega, the derived magnitudes of Vega with the adopted zerop oints, and the inferred fluxes (F ( ) in J y ) for a zero-magnitude star (ie. zero vega mag for BT VT ,U B V RI ,ZV YV ,J H K , Stromgren uv by ; and zero AB mag for Sloan u g r i z and ugr iz filters). The zero magnitude fluxes can b e compared with other values given for instance by Bessell (1979) Bessell & Brett (1998), Cohen et al (2003b), Hewett et al (2006), and the IPAC10 , SPITZER11 and Gemini12 websites. The largest discrepancy is for U, where the 0-mag U-band flux is ab out 4% less than the IPAC value for example, compared to our measured sigma of 2.7%. The zero magnitude fluxes for gr iz and g r i z are close to 3631 Jy, and close to 3680 Jy for u and u . References Azusienis & Straizys, 1969, Sov. Astron. 13, 316 Bessell M. S., 1979, PASP, 91, 589 Bessell M. S., 1991, AJ, 101, 662 Bessell M. S. & Brett J. M., 1998, PASP, 100, 1134 Buser R., 1978, Astr. Astrophys., 62, 411
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http://www.ipac.caltech.edu/2mass/releases/allsky/doc/sec6 4a.html http://casa.colorado.edu/ ginsbura/filtersets.htm http://www.gemini.edu/?q=node/11119


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, R. C., 1996, AJ, 111, 1743 , R. C., 2010, AJ, 139, 1515 , R. C., Dickinson M. E. & Calzetti D., 2001, AJ, 122, 2118 M., Megeath S.T., Hammersley P.L., Fabiola M-L. & Stauffer J., 2003a, AJ, 125, 2645 Cohen M., Wheaton W. M. & Megeath S. T., 2003b, AJ, 126, 1090 Colina L & Bohlin, R. C., 1997, AJ, 113, 1138 Cutri R. M., 1998, AAS 192, 6402 Davenp ort J. R. A., Bochanski J. J., Covey K. R., Hawley S. L., West A. A. & Schneider D. P. 2007, AJ, 134, 2430 Hauck B. & Mermilliod M., 1998, A&AS, 129, 431 Hewett P.C., Warren S.J., Leggett S. K. & Hodgkin S. T., 2006, MNRAS, 367, 454 HÜg E., Fabricius C., Makarov V. V., Urban S., Corbin T., Wycoff G., Bastian U., Schwekendiek P. & Wicenec A., 2000, Astron. Astrophys., 355, 27 Holb erg J.B., & Bergeron P., 2006, AJ, 132, 1221 Lacomb, P. & Fontaine G., 1981, A&AS, 43, 367 Landolt A. U., 1983, AJ, 88, 439 Landolt A. U., 1992a, AJ, 104, 340 Landolt A. U., 1992b, AJ, 104, 372 Landolt A. U., 2007, AJ, 133, 2502 Landolt A. U., 2009, AJ, 137, 4186 Landolt A. U. & Uomoto A. K., 2007, AJ, 133, 768 Maiz Ap ell´niz, J., 2006, AJ, 131, 1184 a Maiz Ap ell´niz, J., 2007, ASP Conference Series, 999, 1 a Menzies J. W., Marang F., Laing J. D., Coulson I. M., Engelbrecht C. A. 1991, MNRAS, 248, 642 Oke J. B. 1990, AJ, 99, 1621 Oke J. B. & Gunn J. E. 1983, ApJ, 266, 71 Pickles A. J., 1998, PASP, 110, 863 Pickles A. J. & Depagne E., 2010, PASP, (submitted) Reach, William T., Megeath, S. T., Cohen, Martin, Hora, J., Carey, Sean, Surace, Jason, Willner, S. P., Barmby, P., Wilson, Gillian, Glaccum, William, Lowrance, Patrick, Marengo, Massimo & Fazio, Giovanni G. 2005, PASP, 117, 978 Sirianni, M., Jee, M. J., Ben´tez, N., Blakeslee, J. P., Martel, A. R., Meurer, G., Clampin, i M., De Marchi, G., Ford, H. C., Gilliland, R., Hartig, G. F., Illingworth, G. D., Mack, J.& McCann, W. J., PASP, 117, 1049 Smith, J. Allyn, Tucker, Douglas L., Kent, Stephen, Richmond, Michael W., Fukugita, Masataka, Ichikawa, Takashi, Ichikawa, Shin-ichi, Jorgensen, Anders M., Uomoto, Alan, Gunn, James E., Hamab e, Masaru, Watanab e, Masaru, Tolea, Alin, Henden, Arne, Annis, James, Pier, Jeffrey R., McKay, Timothy A., Brinkmann, Jon, Chen, Bing, Holtzman, Jon, Shimasaku, Kazuhiro, York, Donald G., 2002, AJ, 123, 212 Smith, J. Allyn, Allam, S. S., Tucker, Douglas L., Stute, J. L, Rodgers, C. T. & Stoughton C., 2005, BAAS, 37, 1379 Sung H. & Bessell M. S., 2000, PASA, 17, 244 Tokunaga A. T., Simons D. A & Vacca W. D. 2002, PASP, 114, 180 Wegner G., 1983, AJ, 88, 109


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Pickles Table 1: ZeroPoints, Zero-Mag fluxes and Selected System/Filter bandpasses

Filter Tycho BT VT Landolt UL BL VL RL IL UBVRI UM U3 BM B3 VM VC RC Rp IC 2MASS J2 H2 K2/S UKIRT ZV YV JMK O HMK O KMK O Ebol Stromgren us vs bs ys Sloan Air u' g' r' i' z' Sloan Vacuum u g r i z

pivot (nm) 419.6 530.6 354.6 432.6 544.5 652.9 810.4 358.9 364.6 437.2 440.2 547.9 549.3 652.7 658.7 789.1 1239.0 1649.5 2163.8 877.6 1020.8 1248.8 1673.0 2200.0 1006.1 346.1 410.7 467.0 547.6 355.2 476.6 622.6 759.8 890.6 355.7 470.3 617.6 749.0 889.2

Nstd 7 5 13 17 17 14 14 13 13 17 17 17 17 14 13 14 15 15 15 5 4 4 5 5 7 6 7 7 12 14 14 13 14 12 14 14 13 14

Filter ZeroPoints Mean Sigma Adopted -0.108 -0.030 0.761 -0.103 -0.014 0.154 0.405 0.763 0.770 -0.116 -0.124 -0.014 -0.014 0.165 0.192 0.386 0.913 1.352 1.830 0.583 0.607 0.936 1.395 1.851 -0.290 -0.316 -0.181 -0.041 -0.033 -0.009 0.004 0.008 0.009 -0.034 -0.002 0.003 0.011 0.007 0.045 0.020 0.038 0.076 0.021 0.039 0.066 0.027 0.050 0.020 0.024 0.010 0.008 0.014 0.031 0.016 0.022 0.024 0.018 0.038 0.031 0.020 0.022 0.038 0.035 0.012 0.024 0.030 0.021 0.027 0.020 0.023 0.018 0.019 0.036 0.019 0.022 0.019 -0.11 -0.03 +0.76 -0.10 -0.014 +0.15 +0.40 +0.76 +0.77 -0.12 -0.12 -0.014 -0.014 +0.17 +0.19 +0.39 +0.91 +1.35 +1.83 +0.58 +0.61 +0.94 +1.40 +1.85 +1.40 -0.29 -0.32 -0.18 -0.04 -0.03 0.00 0.00 0.00 0.00 -0.03 0.00 0.00 0.00 0.00

Vega STIS 005 Mag F (Jy) 0.046 0.016 0.096 -0.004 0.013 0.040 0.050 0.005 -0.050 0.012 0.012 0.019 0.021 0.023 0.025 0.031 -0.016 0.018 0.008 -0.069 -0.011 -0.027 -0.014 0.017 -0.194 1.431 0.189 0.029 0.046 0.974 -0.093 0.148 0.372 0.513 0.961 -0.101 0.142 0.356 0.513 3821 3689 1609 3979 3646 3079 2407 1748 1830 4003 4006 3626 3619 3066 2988 2470 1601 1034 670.3 2268 2092 1570 1019 653.0 1195 1267 4094 4175 3612 1500 3970 3182 2587 2263 1517 3994 3197 2624 2263

0-Mag F (Jy) 3985 3746 1758 3962 3688 3195 2520 1755 1748 4048 4050 3690 3691 3131 3058 2542 1577 1050 674.9 2128 2072 1531 1006 663.1 1000 4734 4871 4288 3768 3680 3643 3648 3644 3631 3676 3640 3645 3641 3631

Selected BandPass * *

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