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J/A+A/527/A77       NGC 1893 optical and NIR photometry      (Prisinzano+, 2011)

Star formation in the outer Galaxy: membership and fundamental parameters of the young open cluster NGC 1893. Prisinzano L., Sanz-Forcada J., Micela G., Caramazza M., Guarcello M.G., Sciortino S., Testi L. <Astron. Astrophys. 527, A77 (2011)> =2011A&A...527A..77P
ADC_Keywords: Clusters, open ; Photometry, UBVRI ; Photometry, infrared ; Photometry, millimetric/submm Keywords: open clusters and associations: individual: NGC 1893 - stars: pre-main sequence - stars: formation - Hertzsprung-Russell and C-M diagrams - infrared: stars Abstract: Different environmental conditions can play a crucial role in determining final products of the star formation process and in this context, less favorable activities of star formation are expected in the external regions of our Galaxy. We studied the properties of the young open cluster NGC 1893 located about 12kpc from the galactic center, to investigate how different physical conditions can affect the process of star formation. By adopting a multiwavelength approach, we compiled a catalog extending from X-rays to NIR data to derive the cluster membership. In addition, optical and NIR photometric properties are used to evaluate the cluster parameters. We find 415 diskless candidate members plus 1061 young stellar objects with a circumstellar disk or class II candidate members, 125 of which are also Hα emitters. Considering the diskless candidate members, we find that the cluster distance is 3.6±0.2kpc and the mean interstellar reddening is E(B-V)=0.6±0.1 with evidence of differential reddening in the whole surveyed region. NGC 1893 contains a conspicuous population of pre-main sequence stars together with the well studied main sequence cluster population; we found a disk fraction of about 70% similar to that found in clusters of similar age in the solar neighbor and then, despite expected unfavorable conditions for star formation, we conclude that very rich young clusters can form also in the outer regions of our Galaxy. Description: We present new optical and NIR photometric data in the VRIJHK and H-α bands for the cluster NGC 1893. The optical photometry was obtained by using images acquired in service mode using two different telescopes: the Device Optimized for the LOw RESolution (DOLORES) mounted on the Telescopio Nazionale Galileo (TNG), used in service mode during three nights in 2007, and the Calar Alto Faint Object Spectrograph (CAFOS), mounted on the 2.2m telescope in Calar Alto German-Spanish Observatory (Spain), during three nights in 2007 and 2008. NIR observations were acquired in service mode at the TNG, using the large field Near Infrared Camera Spectrometer (NICS) with the Js(1.25um), H(1.63um) and K'(2.12um) filters during eight nights in 2007 and 2008. We observed a field around NGC 1893 with a raster of 4x4 pointings, at each pointing we obtained a series of NINT dithered exposures. Each exposure is a repetition of a DIT (Detector Integration Time) times NDIT (number of DIT), to avoid saturation of the background. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table5.dat 76 1068 VRI H-α magnitudes of Class 0/I/II candidate members table6.dat 76 415 VRI H-α magnitudes of diskless candidate members table7.dat 117 1068 Infrared magnitudes of Class 0/I/II candidate members table8.dat 117 415 Infrared magnitudes of diskless candidate members
See also: J/A+A/488/211 : Infrated photometry of NGC 1893 (Caramazza+, 2008) Byte-by-byte Description of file: table5.dat table6.dat
Bytes Format Units Label Explanations
1- 4 I4 --- ID Sequential number 6- 9 I4 --- XID ? Designation from Caramazza et al. (2011, in prep.) 11- 20 F10.7 deg RAdeg Right ascension (J2000.0) 22- 31 F10.7 deg DEdeg Declination (J2000.0) 33- 38 F6.3 mag Vmag ? Landolt V magnitude 40- 44 F5.3 mag e_Vmag ? Error of the Landolt V magnitude 46- 51 F6.3 mag Rmag ? Landolt R magnitude 53- 57 F5.3 mag e_Rmag ? Error of the Landolt R magnitude 59- 64 F6.3 mag Icmag ? Cousins I magnitude 66- 70 F5.3 mag e_Icmag ? Error of the Cousins I magnitude 72- 76 F5.3 mag Hamag ? H-α magnitude
Byte-by-byte Description of file: table7.dat table8.dat
Bytes Format Units Label Explanations
1- 4 I4 --- ID Sequential number 6- 15 F10.7 deg RAdeg Right ascension (J2000.0) 17- 26 F10.7 deg DEdeg Declination (J2000.0) 28- 33 F6.3 mag Jmag ? TNG/NICS Js magnitude 35- 39 F5.3 mag e_Jmag ? Error in Jmag 41- 46 F6.3 mag Hmag ? TNG/NICS H magnitude 48- 52 F5.3 mag e_Hmag ? Error in Hmag 54- 59 F6.3 mag Kmag ? TNG/NICS K' magnitude 61- 65 F5.3 mag e_Kmag ? Error in Kmag 67- 72 F6.3 mag [3.6] ? Magnitude at 3.6um 74- 78 F5.3 mag e_[3.6] ? Error in [3.6] magnitude 80- 85 F6.3 mag [4.5] ? Magnitude at 4.5um 87- 91 F5.3 mag e_[4.5] ? Error in [4.5] magnitude 93- 98 F6.3 mag [5.8] ? Magnitude at 5.8um 100-104 F5.3 mag e_[5.8] ? Error in [5.8] magnitude 106-111 F6.3 mag [8.0] ? Magnitude at 8.0um 113-117 F5.3 mag e_[8.0] ? Error in [8.0] magnitude
Acknowledgements: Loredana Prisinzano, loredana(at)
(End) Patricia Vannier [CDS] 20-Oct-2010
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

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