کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1779017 | 1523750 | 2014 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Sky surface brightness at Mount Graham II. First JHKs science observations with the Large Binocular Telescope Sky surface brightness at Mount Graham II. First JHKs science observations with the Large Binocular Telescope](/preview/png/1779017.png)
• Sky brightness has stronger airmass dependency in the J, H bands than at the Ks-band.
• A correlation was found between the J-band sky background and the fraction of the night.
• At 10 deg from the moon, the J-band sky background can be 0.11 mag brigther.
• Correlation found between the Ks-band sky-brightness and the air temperature.
• At the Ks-band Mt. Graham is the darkest site in the world together with Mauna Kea.
We studied the near-infrared sky-brightness at J, H and Ks-bands as derived from the data taken during the first year and a half of routine science operations of the Large Binocular Telescope (LBT). This is the first comprehensive study of the near-infrared night sky-brightness ever conducted at the Mount Graham International Observatory (MGIO), based on a large dataset comprising 4699 near-infrared images taken in 52 nights. We analyzed the dependency of the near-infrared night sky-brightness with the airmass, the season and the moon phase and distance. The average night sky-brightnesses (dispersion) in the J, H and Ks bands scaled to the zenith is 15.82 mag/arcsec2 (0.21), 14.29 mag/arcsec2 (0.26) and 13.4213.42 mag/arcsec2 (0.32) respectively. Those values were derived for the first time at this observatory. At the J-band we found a tendency of the sky background to get darker by ∼0.35 mag at the end of the night with respect to the evening twilight. Also in the J-band we found that the sky background can be up to ∼0.11 mag brighter when observing at 10°10° distance from the full moon. A correlation was also found between the night sky-brightness in the Ks-band and the air temperature with a gradient of -0.06-0.06 mag per 1°C of temperature increase. If we compare the average sky brightness of the major observing sites we find that, at J-band, Mt. Graham is quite similar to the major sites but it quickly becomes the second darkest place at the H-band and definitely the darkest observing site at the Ks-band together with Mauna Kea.
Journal: New Astronomy - Volume 28, April 2014, Pages 63–69