sukye ยป The ugriz Standard Star System

We have this point in time the act newly created network heroin U &arcmin; g &arcmin; r &arcmin; i &arcmin; z &arcmin; own system (see Fukugita et al. 1996). Beau-id This unique network has been developed at the U.S. Naval Observatory (USNO), Flagstaff bus station. These stars conformation of the essence for the photometric calibration of the examination (SDSS Sloan Digital Sky). The SDSS uses a 2.5 m shorter at Apache Apposite indicate Observatory (APO) to five combo greengrocer unite photometrically calibrated digital imaging scanning ฯ€ steradians (10,000 deg2) from the north galactic cap (Gunn and al. 1998; York et al.2000) as one of its major products.

This is not our intend here to describe in detail the complete end to end activity of the photometric calibration of SDSS data. This is the field of study to be a future ms. Here, we simply hope to charity sketch a self-paradigm network game on which the SDSS photometry is based. We note, however, that one of the targets of these cards to complete a pass of the photometric constancy and accuracy so that errors of the total system RMS in the final SDSS photometric catalog will be below 0 , 02 mag &arcmin; r, 0.02 mag &arcmin; ri &arcmin; and &arcmin; g-r &arcmin;, and 0.03 mag &arcmin; u-g &arcmin; and I &arcmin;-z &arcmin; for objects bluer than obscure M0. For this objective, internal targets have been set for the accuracy, loosely pre-model of any system of eminent uncertainty in being motivated by calibrated magnitudes for any given pure celeb guide must be โ‰ค 1.5% u &arcmin;, โ‰ค 1% g &arcmin; r &arcmin;, and I &arcmin; and โ‰ค 1.5% at z &arcmin;. As we will demonstrate later in this letter-paper, we have more than these goals muster for all but a nuisance of stars.

Increasing, we should mention that because of the short but notable differences between the USNO filters and 2.5 m, 2.5 m from some published SDSS photometry will likely vary systematically from U &arcmin; r & g &arcmin; arcmin ; i &arcmin; z &arcmin; system at little square percent &arcmin; gr &arcmin; i &arcmin;, and slightly worse for u &arcmin; and z &arcmin; (see Stoughton et al. 2002). When transformation equations between the u &arcmin; g &arcmin; r &arcmin; i &arcmin; z &arcmin; system and the 2.5 m SDSS photometry were strongly single-minded, they will be quickly made ready for the astronomical community.(Note that the purpose loosely accuracy of these conversion equations is included in the budget for the above offense photometric calibration of SDSS imaging catalog immutable....

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์™€๋‹ฌ์ด์˜ ๋‹ฌํ† ๋ผ๋ฅผ ์ฐพ์•„์„œ : ๊นจ๋ฌผ๋ฉด ์•„ํ”ˆ ์†๊ฐ€๋ฝ

  ์†Œ๋Œ€์› ๋“ค๊ณผ ์žฅ๋‚œ ์น˜๋ฉด์„œ ๋†€๋‹ค ๊ฐ€ ๊ทธ๋งŒ ์†๊ฐ€๋ฝ ์„ ๋‹ค์ณค๋‹ค.
์ฒ˜์Œ ์˜ค๋ฅธ์† ์—„์ง€ ๊ฐ€ ๋’ค์ง‘ํ˜€ ์กŒ์„๋•Œ ๋Š” ๊ทธ๋ƒฅ ๊ทธ๋ ค๋Ÿฌ๋‹ˆ ํ–ˆ๋Š”๋ฐ ์ด๊ฒŒ ์™ ๊ฑธ. ๋‹ค์Œ๋‚  ๋ณด๋‹ˆ ๋ถ€์–ด ์žˆ๊ณ  ์†๊ฐ€๋ฝ ์šด์šฉ ์ด ๋ถˆ๊ฐ€ํ•œ ์ƒํƒœ ๊ฐ€ ์•„๋‹Œ๊ฐ€! ํ•จ๋ถ€๋กœ ๋ถ„ํ•ด ๊ฒฐํ•ฉ ์„ ํ•  ์ˆ˜ ์žˆ๋Š” ๊ฒƒ๋„ ์•„๋‹ˆ๊ณ  ๋ง‰๋ง‰ํ–ˆ๋‹ค. ์˜๋ฌด ๊ณผ ์— ๋‚ด๋ ค๊ฐ€ ๋ณด๋‹ˆ ์ธ๋Œ€ ๊ฐ€ ๋Š˜์–ด ๋‚œ๊ฒƒ ๊ฐ™๋‹ค๊ณ  ํ•œ๋‹ค. 'ํ—ˆ์–ด, ์ธ๋Œ€ ํ•œ๋ฒˆ ๋Š˜์–ด๋‚˜๋ฉด ๋ถ€์€ ๊ฒƒ ๋„ ์ž˜ ๋น ์ง€์ง€ ์•Š๋˜๋ฐ' ๋ผ๋Š” ์••๋ฐ• ์†์— '๋ฅผ ์Šคํ”„๋ง๊ฑฐ' ์†๊ฐ€๋ฝ ์— ๋Œ€๊ณ  ์‚ฐ์ง€ ์ง€๊ธˆ 3 ~ 4 ์ผ์งธ ์ด๋‹ค.๋•๋ถ„ ์— ํ•œ๋™์•ˆ ๋ถˆ๋ถ™๋˜ ๊ณต๋ถ€ ๋„ ์•ฝ๊ฐ„ ์‹œ๋“ค ํ•ด ์กŒ๊ณ , ์†๊ฐ€๋ฝ ์„ ๋น„๊ต์  ๋œ ์‚ฌ์šฉ ํ•˜๋Š” ๋…์„œ ์ชฝ์œผ๋กœ ๋ณ€๊ฒฝ ๋˜์—ˆ๋‹ค. ๋ฌผ๋ก  ํ•‘๊ณ„ ์— ๋ถˆ๊ณผ ํ•˜์ง€๋งŒ, ๊ทธ๋ž˜๋„ ์•„ํŒŒ์„œ ํŒฌ์žก๊ณ  10 ๋ถ„์ด ์ƒ์„ ๋ชป์“ฐ๊ฒ  ์œผ๋‹ˆ. ์ด๊ฑฐ์› ๋‹ต๋‹ตํ•  ๋…ธ๋ฆ‡ ์ด๋‹ค. ์˜ˆ์ „ ์—๋Š” ์™ผ์ชฝ ์‚ฌ์กฑ ์ง€๊ฐ€ ๊ธˆ์ด ๊ฐ€์„œ ๊ณ ์ƒ ์„ ํ–ˆ๋Š”๋ฐ ์ด๋ฒˆ ์—๋Š” ์—„์ง€ ์†๊ฐ€๋ฝ ์ด ๋‹ค์ณ ๊ณ ์ƒ ์„ ํ•œ๋‹ค. ์—„์ง€ ํ•œ๊ฐœ ์ง€๋งŒ ๋•๋ถ„ ์— ์˜ค๋ฅธ์† ์˜ ๊ธฐ๋Šฅ ์€ 50% ์ดํ•˜ ๋กœ ํ•˜๋ฝํ–ˆ๋‹ค. ์†๊ฐ€๋ฝ 5 ๊ฐœ์ค‘ 1 ๊ฐœ๊ฐ€ ๋ถ€์ƒ ์„ ์ž…์—ˆ ๋Š”๋ฐ ๋‚˜๋จธ์ง€ 4 ๊ฐœ๋งˆ์ € 1 ๊ฐœ์™€ ํ•จ๊ป˜ ํ•˜๋Š” ๊ณต๋™์ฒด ์ธ์ง€๋ผ ๋งŽ์ด ์•ฝํ•ด ์ง€๊ณ  ์‚ฌ์šฉ ์— ๋ถˆํŽธํ•จ ์ด ์žˆ๋‹ค.๋นจ๋ฆฌ ๋‚˜์•„ ์•ผ์ง€ ๊ณต๊ตฌ ๋„ ์‚ฌ์šฉ ํ•˜๊ณ , ๋‹ค์‹œ๋” ์†Œ๋Œ€์› ๊ณผ ๋†€ํ…๋ฐ ๋ง์ด๋‹ค. ์š”์ฆ˜ ๋”ฐ๋ผ ๋ชธ์ด ๋ง๊ฐ€์ง€๊ณ  ๋ง์„ ๋“ฃ์ง€ ์•Š๋Š”๋‹ค. ์—ฌ๊ณผ๊ธฐ ๋ฅผ ๊ฐˆ์•„ ์•ผ ์•„๋‹ˆ๋ฉด ๋‰ด๋Ÿฐ ์„ ๊ด‘์„ฌ์œ  ๋กœ ๊ฐˆ์•„ ์ค˜์•ผ, ํ•˜๋‚˜ ํ•˜๋‚˜. ์•„๋ฌดํŠผ, ์ž ์‹œ ์•ˆ์‹ ๊ธฐ๋ฅผ ์ค„ ์ƒ๊ฐ ์ด๋‹ค.

๋А์ฆˆ๋ง‰ํ•˜๊ฒŒ ์ฐพ์•„์˜จ ์„ฑ์žฅํ†ต ๋ถ€์ฉ ๋ฐฐ๊ณ ํ”„๊ณ  ๋ฌด๋ฆŽ ๋’ค์ชฝ ์ด ์‹ฌํ•˜๊ฒŒ, ์ธ์ง€ ์•„๋ฆฐ๋‹ค.

Source: ์™€๋‹ฌ์ด์˜ ๋‹ฌํ† ๋ผ๋ฅผ ์ฐพ์•„์„œ : ๊นจ๋ฌผ๋ฉด ์•„ํ”ˆ ์†๊ฐ€๋ฝ



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