J/A+A/581/A47 Lines and continuum sky emission in the NIR (Oliva+, 2015) Lines and continuum sky emission in the near infrared: observational constraints from deep high spectral resolution spectra with GIANO-TNG. Oliva E., Origlia L., Scuderi S., Benatti S., Carleo I., Lapenna E., Mucciarelli A., Baffa C., Biliotti V., Carbonaro L., Falcini G., Giani E., Iuzzolino M., Massi F., Sanna N., Sozzi M., Tozzi A., Ghedina A., Ghinassi F., Lodi M., Harutyunyan A., Pedani M. =2015A&A...581A..47O ADC_Keywords: Spectra, infrared ; Spectroscopy Keywords: line: identification - instrumentation: spectrograph - infrared: general - techniques: spectroscopic Abstract: Determining the intensity of lines and continuum airglow emission in the H-band is important for the design of faint-object infrared spectrographs. Existing spectra at low/medium resolution cannot disentangle the true sky-continuum from instrumental effects (e.g. diffuse light in the wings of strong lines). We aim to obtain, for the first time, a high resolution infrared spectrum deep enough to set significant constraints on the continuum emission between the lines in the H-band. During the second commissioning run of the GIANO high-resolution spectrograph at the La Palma Observatory, we pointed the instrument directly to the sky and obtained a deep spectrum that extends from 0.97 to 2.4 micron and includes the whole H-band. The spectrum shows about 1500 emission lines, a factor of two more than in previous works. Of these, 80% are identified as OH transitions; half of these are from highly excited molecules (hot-OH component). The other lines are attributable to O2 or unidentified. Several of the faint lines are in spectral regions that were previously believed to be free of lines emission. The continuum in the H-band is marginally detected at a level of about 300photons/m2/s/arcsec2/um. The observed spectrum and the list of observed sky-lines are published in electronic format. Our measurements indicate that the sky continuum in the H-band could be even darker than previously believed. However, the myriad of airglow emission lines severely limits the spectral ranges where very low background can be effectively achieved with low/medium resolution spectrographs. We identify a few spectral bands that could still remain quite dark at the resolving power foreseen for VLT-MOONS (R∼6,600). Description: Tables 1 and 2 list the wavelengths and relative photon fluxes of the OH airglow lines (Table 1) and the wavelengths and relative photon fluxes of other airglow lines (Table 2), measured in the Near-Infrared with the echelle spectrometer GIANO at the Telescopio Nazionale Galileo. The intensities of the lines (flux) are expressed in units of photons/m2/s, normalised to the intensity of the brightest line (in Table1), which is set to 104. The wavelengths are in vacuum and expressed in Angstrom. The Wavelengths in Table 1 are computed from the most complete and accurate OH molecular parameters available in the literature (Bernath & Colin, 2009, J. Mol. Spec., 257, 20). Table 4 contains the observed spectrum in the Y,J and H photometric bands. The wavelengths are in vaccuum and in Angstrom. The spectral flux is expressed in units of photons/m2/s/Angstrom, please note that the flux calibration is uncertain (see the paper for details). File Summary: FileName Lrecl Records Explanations ReadMe 80 . This file table1.dat 55 603 OH airglow line wavelengths and relative fluxes table2.dat 30 293 *Non-OH line wavelengths and relative fluxes table4.dat 18 49864 Airglow spectrum covering the Y, J, H-bands Note on table2.dat: Identification based on the HITRAN database. Byte-by-byte Description of file: table1.dat Bytes Format Units Label Explanations 1- 9 F9.3 0.1nm lambda1 [9792/22984] Vacuum wavelength of the first line of the doublet (Å) 11- 24 A14 --- Iden1 Line identification (1) 26- 34 F9.3 0.1nm lambda2 [9791/22988] Vacuum wavelength of the second line of the doublet (Å) 36- 49 A14 --- Iden2 Line identification (1) 51- 55 I5 --- Flux [3/10000] Relative line photon flux of doublet Note (1): Lines are grouped in pairs, one for each lambda-doublet. Byte-by-byte Description of file: table2.dat Bytes Format Units Label Explanations 1- 8 F8.2 0.1nm lambda [10489/21794] Vacuum wavelength (Å) 11- 22 A12 --- Iden Line identification 26- 28 I3 --- Flux [4/820] Relative line photon flux 30 A1 --- Flag [a-l] Notes to individual lines (1) Note (1): Notes as follows: a = broad b = scales like O2 lines c = blend with OH [7-4]P1(7.5) d = blend e = blend with OH [8-5]R1(3.5) f = blend with [8-5]R1(2.5) g = blend with [8-5]R1(1.5) h = possible doublet i = broad, asymmetric j = blend with OH [4,2]P2(9.5) k = blend with OH [4-2]Q1f(3.5) l = blend with OH [6,4]R1(16.5)) Byte-by-byte Description of file: table4.dat Bytes Format Units Label Explanations 1- 9 F9.3 0.1nm lambda [9790/18022] Vacuum wavelength (Å) 11- 18 F8.4 10/m2/s/nm Flux [-1/421] Spectral flux (photons/m2/s/Å) Acknowledgements: Ernesto Oliva, oliva(at)arcetri.astro.it, Fabrizio Massi, fmassi(at)arcetri.astro.it (End) Ernesto Oliva [INAF - Arcetri], Patricia Vannier [CDS] 09-Jul-2015 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 © Université de Strasbourg/CNRS     • Contact