J/AJ/161/256 MYSST. I. HST F555W and F814W obs. of N44 in LMC (Ksoll+, 2021)
Measuring Young Stars in Space and Time.
I. The photometric catalog and extinction properties of N44.
Ksoll V.F., Gouliermis D., Sabbi E., Ryon J.E., Robberto M., Gennaro M.,
Klessen R.S., Koethe U., De Marchi G., Chen C.-H.R., Cignoni M.,
Dolphin A.E.
<Astron. J., 161, 256-256 (2021)>
=2021AJ....161..256K 2021AJ....161..256K (SIMBAD/NED BibCode)
ADC_Keywords: Photometry, HST; Magellanic Clouds; Star Forming Region; Surveys;
Optical
Keywords: Pre-main sequence stars; Large Magellanic Cloud; Star-forming regions
HST photometry; Young star clusters; Low mass stars; Surveys
Abstract:
In order to better understand the role of high-mass stellar feedback
in regulating star formation in giant molecular clouds, we carried out
a Hubble Space Telescope (HST) Treasury Program Measuring Young Stars
in Space and Time (MYSST) targeting the star-forming complex N44 in
the Large Magellanic Cloud (LMC). Using the F555W and F814W broadband
filters of both the ACS and WFC3/UVIS, we built a photometric catalog
of 461684 stars down to mF555W∼29mag and mF814W∼28mag,
corresponding to the magnitude of an unreddened 1Myr pre-main-sequence
star of ∼0.09M☉ at the LMC distance. In this first paper we
describe the observing strategy of MYSST and the data reduction
procedure and present the photometric catalog. We identify multiple
young stellar populations tracing the gaseous rim of N44's
superbubble, together with various contaminants belonging to the LMC
field population. We also determine the reddening properties from the
slope of the elongated red clump (RC) feature by applying the
machine-learning algorithm RANSAC, and we select a set of
upper-main-sequence stars as primary probes to build an extinction
map, deriving a relatively modest median extinction AF555W∼0.77mag.
The same procedure applied to the RC provides AF555W∼0.68 mag.
Description:
The Hubble Space Telescope (HST) Treasury Program Measuring Young
Stars in Space and Time (MYSST; GO-14689, P.I. Gouliermis) is a deep,
high spatial resolution HST survey of the star-forming complex N44
located in the LMC. It covers the large superbubble of N44, as well as
the region south of it, with a field of view (FOV) of
12.2x14.7arcmin2. The survey provides observations in two broadband
filters, F555W and F814W, with the Advanced Camera for Surveys (ACS)
and Wide Field Camera 3 (WFC3, UVIS channel) instruments of HST.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
catalog.dat 206 461684 MYSST photometric catalog
--------------------------------------------------------------------------------
See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJ/452/210 : UBV photometry in LH 47/48 (Oey+ 1995)
J/AcA/49/223 : BVI photometry of OGLE LMC Cepheids (Udalski+, 1999)
J/AcA/49/437 : BVI photometry of OGLE SMC Cepheids (Udalski+, 1999)
J/AJ/128/1606 : Magellanic Clouds Photometric Survey: the LMC (Zaritsky+, 2004)
J/ApJ/695/511 : Young massive stars in LHA 120-N 44 (Chen+, 2009)
J/A+A/530/A115 : Rotating massive MS stars evolutionary models (Brott+, 2011)
J/ApJ/738/137 : HST VI stars in Shapley Constellation III (Gouliermis+, 2011)
J/ApJS/197/16 : CO observations of LMC molecular clouds (MAGMA). (Wong+, 2011)
J/A+A/542/A66 : YSOs in 9 LMC star forming regions (Carlson+, 2012)
J/ApJ/755/154 : Mass accretion rates from HST in the ONC (Manara+, 2012)
J/A+A/553/A24 : Models for rotating stars (Georgy+, 2013)
J/ApJS/207/10 : HST Treasury Program on the ONC (Robberto+, 2013)
J/ApJS/222/11 : Hubble Tarantula Treasury Project (HTTP). III. (Sabbi+, 2016)
J/MNRAS/472/1760 : Hierarchical formation of Westerlund 1 (Gennaro+, 2017)
J/ApJ/854/154 : N159 12CO and 13CO (2-1) clumps (Nayak+, 2018)
J/MNRAS/476/1213 : Ages for stars in 19 clusters (Getman+, 2018)
http://archive.stsci.edu/hlsp/mysst : MYSST data on MAST
Byte-by-byte Description of file: catalog.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- --- [MYSST]
7- 25 A19 --- MYSST MYSST identifier (HHMMSS.ss+DDMMSS.ss; J2000)
27- 35 F9.3 pix Xpos [87/28804] Pixel coordinate X in WFC3/UVIS
reference image
37- 45 F9.3 pix Ypos [213/26257] Pixel coordinate Y in WFC3/UVIS
reference image
47- 56 F10.7 deg RAdeg [80.3/81.2] Right ascension (J2000)
58- 68 F11.7 deg DEdeg [-68.2/-67.8] Declination (J2000)
70- 74 F5.2 --- Chi2 [0.5/19.3] Chi squared PSF fit quality for
combined data
76- 81 F6.1 --- SNR [4/4358] S/N for combined data
83- 88 F6.3 --- shrp [-0.74/0.34] Sharpness for combined data
90- 94 F5.3 --- rnd [0/10] Roundness for combined data
96- 98 I3 deg mjaxdir [0/175] Direction of major axis (if not round)
for combined data
100- 104 F5.3 --- crwd [0/2.8] Crowding for combined data
106 I1 --- Type [1] DOLPHOT object type
(always "1" = bright star)
108- 113 F6.3 mag F555Wmag [13.94/29.31] HST/WFC3 F555W band magnitude
115- 119 F5.3 mag e_F555Wmag [0.001/0.22] Uncertainty in F555Wmag
121- 126 F6.2 --- Chi2F555 [0.3/204] χ2 PSF fit quality for F555W
128- 133 F6.1 --- SNR555 [4.9/1871] Signal-to-noise ratio for F555W
135- 140 F6.3 --- shrp555 [-0.7/0.3] Sharpness for F555W
142- 147 F6.3 --- rnd555 [-1.12/9.16] Roundness for F555W
149- 153 F5.3 mag crwd555 [0/0.25] Crowding for F555W
155 I1 --- q_F555Wmag [0/3] Photometry quality flag for F555Wmag
(0=good) (1)
157- 162 F6.3 mag F814Wmag [13.02/28.2] HST/WFC3 F814W band magnitude
164- 168 F5.3 mag e_F814Wmag [0.001/0.22] Uncertainty on the F814Wmag
170- 175 F6.2 --- Chi2F814 [0.1/219] χ2 PSF fit quality for F814W
177- 182 F6.1 --- SNR814 [5/2171] Signal-to-noise ratio for F814W
184- 189 F6.3 --- shrp814 [-0.7/0.3] Sharpness for F814W
191- 196 F6.3 --- rnd814 [-1.85/9.62] Roundness for F814W
198- 202 F5.3 mag crwd814 [0/0.25] Crowding for F814W
204 I1 --- q_F814Wmag [0/3] Photometry quality flag for F814Wmag
(0=good) (1)
206 I1 --- Orgn [0/4] Photometry origin flag (2)
--------------------------------------------------------------------------------
Note (1): DOLPHOT photometry bit flags:
0 = star well recovered in the image
1 = photometry aperture extends off chip
2 = too many bad or saturated pixels
See DOLPHOT manual: http://americano.dolphinsim.com/dolphot/dolphot.pdf
Note (2): Photometry origin flag as follows:
0 = Aperture photometry used, without matching PSF GST source (176 stars)
1 = Aperture photometry used, with matching PSF GST source (750 stars)
2 = PSF photometry, aperture blended (360 stars)
3 = PSF photometry, high S/N but no aperture detection (77 stars)
4 = PSF photometry, low S/N (460321 stars)
--------------------------------------------------------------------------------
History:
Downloaded from: http://archive.stsci.edu/hlsp/mysst
(End) Emmanuelle Perret [CDS] 12-Aug-2021