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J/ApJ/707/1347         HST F160W photometry in RMC 136         (Andersen+, 2009)

The low-mass initial mass function in the 30 Doradus starburst cluster. Andersen M., Zinnecker H., Moneti A., McCaughrean M.J., Brandl B., Brandner W., Meylan G., Hunter D. <Astrophys. J., 707, 1347-1360 (2009)> =2009ApJ...707.1347A
ADC_Keywords: Clusters, globular ; Photometry, HST ; Stars, pre-main sequence ; Magellanic Clouds Keywords: globular clusters: individual (30 Doradus) - stars: formation - stars: luminosity function, mass function - stars: pre-main sequence Abstract: We present deep Hubble Space Telescope NICMOS 2 F160W band observations of the central 56"x57" (14pcx14.25pc) region around R136 in the starburst cluster 30 Dor (NGC 2070) located in the Large Magellanic Cloud. Our aim is to derive the stellar initial mass function (IMF) down to ∼1M in order to test whether the IMF in a massive metal-poor cluster is similar to that observed in nearby young clusters and the field in our Galaxy. We estimate the mean age of the cluster to be 3Myr by combining our F160W photometry with previously obtained HST WFPC2 optical F555W and F814W band photometry and comparing the stellar locus in the color-magnitude diagram with main sequence and pre-main sequence isochrones. The color-magnitude diagrams show the presence of differential extinction and possibly an age spread of a few megayear. We convert the magnitudes into masses adopting both a single mean age of 3Myr isochrone and a constant star formation history from 2 to 4Myr. We derive the IMF after correcting for incompleteness due to crowding. The faintest stars detected have a mass of 0.5M and the data are more than 50% complete outside a radius of 5pc down to a mass limit of 1.1M for 3Myr old objects. Description: We have obtained HST/NICMOS Camera 2 images through the F160W band of the central 56"x57" region around R136 in the 30 Dor cluster (HST program ID 7370). The observations were centered on the cluster (R.A., decl.) = (05:38:43.3,-69:06:08) and on two adjacent control fields centered on (05:38:42.4,-68:52:00), and (05:38:56.9,-68:52:00). The observing dates were 1997 October 14 and 16. The field of view of the 256x256 pixel NICMOS Camera 2 is 19"x19" with a pixel scale of 0.075". Objects: ------------------------------------------- RA (2000) DE Designation(s) ------------------------------------------- 05 38 42.4 -69 06 03 RMC 136 = * 30 Dor ------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 28 10108 The F160W band detected sources in R 136
See also: II/187 : 30 Doradus OB Associations (Parker 1992) J/ApJS/191/160 : 3D spectroscopy in 30 Dor (Pellegrini+, 2010) J/ApJ/703/736 : Clump properties in the LMC 30 Dor region (Pineda+, 2009) J/ApJ/707/1347 : HST F160W photometry in RMC 136 (Andersen+, 2009) J/AJ/131/2164 : X-ray sources in RMC 136 (Townsley+, 2006) J/A+A/443/851 : Effective temperature of 30 Dor population (Selman+, 2005) J/A+A/438/663 : JHKL photometry of 30 Dor (Maercker+, 2005) J/ApJ/466/254 : NIR Imaging of R136 in 30 Dor (Brandl+ 1996) J/AJ/107/1054 : UBV photometry of the 30 Dor region (Malumuth+, 1994) J/ApJ/413/604 : 30 Dor (Hill+, 1993) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 8 F8.3 pix Xpix The center X pixel (1) 10- 17 F8.3 pix Ypix The center Y pixel (1) 19- 23 F5.2 mag F160W HST/NICMOS F160W band magnitude 25- 28 F4.2 mag e_F160W Error in F160Wmag
Note (1): 1pix=0.075" and each position in a 3x3 mosaic centered on R136 (J053843.3-690608) was observed 4 times with small dithers of ∼16pix.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 04-Jan-2012
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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