J/ApJS/235/23 LEGUS galaxies1 observations (Sabbi+, 2018)
The resolved stellar populations in the LEGUS galaxies1.
Sabbi E., Calzetti D., Ubeda L., Adamo A., Cignoni M., Thilker D.,
Aloisi A., Elmegreen B.G., Elmegreen D.M., Gouliermis D.A., Grebel E.K.,
Messa M., Smith L.J., Tosi M., Dolphin A., Andrews J.E., Ashworth G.,
Bright S.N., Brown T.M., Chandar R., Christian C., Clayton G.C., Cook D.O.,
Dale D.A., De Mink S.E., Dobbs C., Evans A.S., Fumagalli M.,
Gallagher J.S., Grasha K., Herrero A., Hunter D.A., Johnson K.E., Kahre L.,
Kennicutt R.C., Kim H., Krumholz M.R., Lee J.C., Lennon D., Martin C.,
Nair P., Nota A., Ostlin G., Pellerin A., Prieto J., Regan M.W., Ryon J.E.,
Sacchi E., Schaerer D., Schiminovich D., Shabani F., Van Dyk S.D.,
Walterbos R., Whitmore B.C., Wofford A.
<Astrophys. J. Suppl. Ser., 235, 23-23 (2018)>
=2018ApJS..235...23S 2018ApJS..235...23S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry; Photometry, HST; Photometry, ultraviolet;
Photometry, UBVRI
Keywords: galaxies: star clusters: general; galaxies: star formation
galaxies: stellar content; Hertzsprung-Russell and C-M diagrams
stars: formation
Abstract:
The Legacy ExtraGalactic UV Survey (LEGUS) is a multiwavelength Cycle
21 Treasury program on the Hubble Space Telescope. It studied 50
nearby star-forming galaxies in 5 bands from the near-UV to the
I-band, combining new Wide Field Camera 3 observations with archival
Advanced Camera for Surveys data. LEGUS was designed to investigate
how star formation occurs and develops on both small and large scales,
and how it relates to the galactic environments. In this paper we
present the photometric catalogs for all the apparently single stars
identified in the 50 LEGUS galaxies. We present optical and near-UV
color-magnitude diagrams for all the galaxies. For each galaxy we
derived the distance from the tip of the red giant branch. We then
used the NUV color-magnitude diagrams to identify stars more massive
than 14M☉, and compared their number with the number of massive
stars expected from the GALEX FUV luminosity. Our analysis shows that
the fraction of massive stars forming in star clusters and stellar
associations is about constant with the star formation rate. This lack
of a relation suggests that the timescale for evaporation of unbound
structures is comparable or longer than 10Myr. At low star formation
rates this translates to an excess of mass in clustered environments
as compared to model predictions of cluster evolution, suggesting that
a significant fraction of stars form in unbound systems.
Description:
The Legacy ExtraGalactic UV Survey (LEGUS) is a multiwavelength Cycle
21 Treasury program on the Hubble Space Telescope (HST). LEGUS was
awarded 154 orbits in Cycle 21 to observe 50 star-forming galaxies
with the UVIS channel of the Wide Field Camera 3 (WFC3) in the filters
F275W, F336W, and when not already available in the Mikulski Archive
for the Space Telescope (MAST) archive, also in the filters F438W,
F555W, and F814W. For simplicity, from now on, in the text we will
refer to these filters as NUV, U, B, V, and I, respectively.
To increase the legacy value of the project, ACS archival data in the
filters B, V, and/or I have been aligned to the LEGUS data.
See the log of the observations in Table 1 (spanning November 2002 to
September 2014).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 92 1088 Log of the observations
table4.dat 105 63 Properties of the LEGUS galaxies
catlegus.dat 335 39127740 Five band stellar photometry catalog for only
the sources with error_type=0 for all the LEGUS
galaxies
phot/* . 63 Original ASCII individual files for the 63 LEGUS
galaxies
--------------------------------------------------------------------------------
See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
J/ApJ/841/92 : Young massive star clusters in 2 LEGUS galaxies (Ryon+, 2017)
J/ApJ/827/33 : PHAT. XVI. Star cluster masses and ages (Johnson+, 2016)
J/AJ/152/50 : Cosmicflows-3 catalog (CF3) (Tully+, 2016)
J/ApJ/812/147 : Star clusters in NGC 628 + 7793 (Krumholz+, 2015)
J/A+A/529/A25 : Photom. of star clusters in 5 nearby gal. (Silva-Villa+, 2011)
J/ApJS/192/6 : A GALEX UV imaging survey of nearby galaxies (Lee+, 2011)
J/MNRAS/405/857 : Star clusters in NGC 3256 (Goddard+, 2010)
J/ApJ/706/599 : Hα and UV SFR in the local volume (Lee+, 2009)
J/AJ/138/332 : LEDA CMD/tip of the red giant branch (Jacobs+, 2009)
J/ApJS/178/247 : Hα and [NII] survey in local 11 Mpc (Kennicutt+, 2008)
J/ApJ/667/L145 : HST Photometry of M82 region B (Smith+, 2007)
J/ApJ/658/1006 : Radial profiles for 161 face-on spirals (Munoz-Mateos+, 2007)
J/ApJ/650/88 : NGC 4395 light curves. III. (Desroches+, 2006)
J/AJ/123/3154 : RV light curves of variable stars in Leo A (Dolphin+, 2002)
J/AJ/121/3048 : Multicolor photometry in NGC 1512 and NGC 5248 (Maoz+, 2001)
J/AJ/114/2381 : UBVI photometry of NGC 7252 (Miller+, 1997)
http://archive.stsci.edu/prepds/legus/dataproducts-public.html : LEGUS data
(doi:10.17909/T9J01Z)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name LEGUS galaxy name
14- 22 A9 --- Dataset Dataset name
24- 28 I5 --- Prop [9490/13364] HST Proposal ID
30- 39 A10 "D/M/Y" Obs.date Observation date
41- 48 A8 "h:m:s" Obs.time Observation datetime
50- 51 I2 h RAh Hour of Right Ascension (J2000)
53- 54 I2 min RAm Minute of Right Ascension (J2000)
56- 59 F4.1 s RAs Second of Right Ascension (J2000)
61 A1 --- DE- Sign of the Declination (J2000)
62- 63 I2 deg DEd Degree of Declination (J2000)
65- 66 I2 arcmin DEm Arcminute of Declination (J2000)
68- 71 F4.1 arcsec DEs Arcsecond of Declination (J2000)
73- 80 A8 --- Inst Instrument (WFC3 or ACS)
82- 86 A5 --- Filt Filter (F275W to F814W)
88- 92 I5 s Exp [90/1490] Exposure time
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name LEGUS galaxy name
14- 16 A3 --- f_Name Flag(s) on Name (1)
18- 21 F4.1 --- TType [0.1/11] RC3 morphological T-type
23- 28 E6.2 Msun M* Stellar mass
30- 35 E6.2 Msun MHI [10/1.9e+10] HI mass
37- 42 F6.4 Msun/yr SFR [0.004/5.1] UV SFR corrected for
dust attenuation (2)
44- 48 F5.1 arcsec Rfuv [0/173] GALEX FUV half-light radius R1/2
50- 53 F4.2 mag E(B-V)0 [0.01/0.08] The foreground E(B-V)
55- 58 F4.2 mag E(B-V) [0.02/0.4] E(B-V) value (3)
60- 65 F6.4 --- Z [0.0008/0.02] Metallicity (4)
67- 71 F5.2 mag (m-M)0 [27.5/31.3] Distance modulus (see section 4)
73- 76 F4.2 mag e_(m-M)0 [0.2/0.6] (m-M)0 uncertainty
78- 82 F5.2 Mpc Dist [3.3/18] Distance
84- 87 F4.2 Mpc e_Dist [0.2/2] Dist uncertainty
89- 93 I5 --- N14m [7/10148] Number of stars more massive that
14M☉ found in the field of each galaxy
(see section 5)
95-105 A11 --- Gal Galaxy name as used in filenames;
column added by CDS
--------------------------------------------------------------------------------
Note (1): Flag as follows:
b = Galaxies used to evaluate the relation between Γ* and
the ΣSFR.
u = Galaxies for which the derived distance is uncertain.
Note (2): The SFR corrected for dust attenuation derived from the Galex FUV
flux, assuming a Kroupa initial mass function.
Note (3): The E(B-V) values derived from the comparison of the upper
MS colors with the models.
Note (4): The metallicity Z as inferred from the comparison of the optical CMDs
with PARSEC isochrones.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: catlegus.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Gal Galaxy name; column added by CDS
12- 20 F9.3 pix Ximg Object position along x (X_IMAGE)
22- 30 F9.3 pix Yimg Object position along y (Y_IMAGE)
33- 38 F6.3 mag F275W [15.8/34.4]?=0 HST/WFC3 UVIS F275W DOLPHOT
magnitude in VEGA system (MAGNI_F275W)
41- 45 F5.3 mag e_F275W [0.001/9.999]?=0 Magnitude error (MAGER_F275W)
48- 53 F6.3 --- Chi2a [0/77.5] Reduced chi2 from PSF-fitting
(CHISQ_F275W)
56- 61 F6.3 --- Sharpa [-9.999/9.999] Object sharpness
(0=perfect stellar fit) (SHARP_F275W)
64- 68 F5.3 mag Crowda [0/9.999] Object crowding (0=isolated star)
(CROWD_F275W)
70- 75 F6.3 --- Rounda [-1.2/9.999] Object roundness (ROUND_F275W)
78 I1 --- OTa [0/2] Object type (OTYPE_F275W)
81- 86 F6.3 mag F336W [15.4/34.5]?=0 HST/WFC3 UVIS F336W DOLPHOT
magnitude in VEGA system (MAGNI_F336W)
89- 93 F5.3 mag e_F336W [0.001/9.999]?=0 Magnitude error (MAGER_F336W)
96-101 F6.3 --- Chi2b [0/82] Reduced chi2 from PSF-fitting
(CHISQ_F336W)
104-109 F6.3 --- Sharpb [-9.999/4.2] Object sharpness
(0=perfect stellar fit) (SHARP_F336W)
112-116 F5.3 mag Crowdb [0/5.7] Object crowding (0=isolated star)
(CROWD_F336W)
118-123 F6.3 --- Roundb [-0.5/9.999] Object roundness (ROUND_F336W)
126 I1 --- OTb [0/2] Object type (OTYPE_F336W)
129-134 F6.3 mag F438W [16.7/36]?=0 HST/WFC3 UVIS F438W DOLPHOT
magnitude in VEGA system (MAGNI_F438W)
137-141 F5.3 mag e_F438W [0.001/9.999]?=0 Magnitude error (MAGER_F438W)
144-149 F6.3 --- Chi2c [0/75] Reduced chi2 from PSF-fitting
(CHISQ_F438W)
152-157 F6.3 --- Sharpc [-9.999/2.8] Object sharpness
(0=perfect stellar fit) (SHARP_F438W)
160-164 F5.3 mag Crowdc [0/5.7] Object crowding (0=isolated star)
(CROWD_F438W)
166-171 F6.3 --- Roundc [-0.5/9.999] Object roundness (ROUND_F438W)
174 I1 --- OTc [0/2] Object type (OTYPE_F438W)
177-182 F6.3 mag F555W [17.7/30]?=0 HST/WFC3 UVIS F555W DOLPHOT
magnitude in VEGA system (MAGNI_F555W)
185-189 F5.3 mag e_F555W [0.001/9.999]?=0 Magnitude error (MAGER_F555W)
192-197 F6.3 --- Chi2d [0/80] Reduced chi2 from PSF-fitting
(CHISQ_F555W)
200-205 F6.3 --- Sharpd [-9.999/4.8] Object sharpness
(0=perfect stellar fit) (SHARP_F555W)
208-212 F5.3 mag Crowdd [0/6.2] Object crowding (0=isolated star)
(CROWD_F555W)
214-219 F6.3 --- Roundd [-1.2/9.999] Object roundness (ROUND_F555W)
222 I1 --- OTd [0/2] Object type (OTYPE_F555W)
225-230 F6.3 mag F814W [16.3/30]?=0 HST/WFC3 UVIS F814W DOLPHOT
magnitude in VEGA system (MAGNI_F814W)
233-237 F5.3 mag e_F814W [0.001/9.999]?=0 Magnitude error (MAGER_F814W)
240-245 F6.3 --- Chi2e [0/80] Reduced chi2 from PSF-fitting
(CHISQ_F814W)
248-253 F6.3 --- Sharpe [-9.999/28.2] Object sharpness
(0=perfect stellar fit) (SHARP_F814W)
256-260 F5.3 mag Crowde [0/5.8] Object crowding (0=isolated star)
(CROWD_F814W)
262-267 F6.3 --- Rounde [-1.2/9.999] Object roundness (ROUND_F814W)
270 I1 --- OTe [0/2] Object type (OTYPE_F814W)
274-278 I5 --- Flags [1/55555] Five bands flag for LEGUS selections
(GPQFs) (1)
282-292 F11.7 deg RAdeg Right ascension of barycenter (J2000)
(ALPHA_J2000)
296-306 F11.7 deg DEdeg Declination of barycenter (J2000) (DELTA_J2000)
308-312 A5 --- --- [LEGUS]
313-335 A23 --- LEGUS LEGUS unique identifier
(+HH:MM:SS.SS-DD:MM:SS.S) (LEGUS_ID)
--------------------------------------------------------------------------------
Note (1): One digit per filter for NUV, U, B, V, and I (from left to right)
good photometric quality flag (GPQF). "0" corresponds to a
non-detection. A source that passed all the selection criteria in all
five bands will have GPQF=55555; see section 2.5 for further details.
--------------------------------------------------------------------------------
History:
From electronic version of the journal for tables 1 and 4.
hlsplegushstwfc3{gal}multibandv2_stellar-phot.cat downloaded from:
http://archive.stsci.edu/prepds/legus/dataproducts-public.html (catlegus.dat)
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 23-Aug-2018