J/AJ/142/129 HST photometry of NGC 4449 clusters (Annibali+, 2011)
The cluster population of the irregular galaxy NGC 4449 as seen by the
Hubble Advanced Camera for Surveys.
Annibali F., Tosi M., Aloisi A., Van Der Marel R.P.
<Astron. J., 142, 129 (2011)>
=2011AJ....142..129A 2011AJ....142..129A
ADC_Keywords: Galaxies, photometry ; Photometry, HST
Keywords: galaxies: dwarf - galaxies: individual (NGC 4449) -
galaxies: irregular - galaxies: starburst -
galaxies: star clusters: general
Abstract:
We present a study of the star cluster population in the starburst
irregular galaxy NGC 4449 based on B, V, I, and Hα images taken
with the Advanced Camera for Surveys on the Hubble Space Telescope. We
derive cluster properties such as size, ellipticity, and total
magnitude. Cluster ages and masses are derived fitting the observed
spectral energy distributions with different population synthesis
models.
Description:
The observations were performed in 2005 November with the ACS/WFC
using the F435W (B), F555W (V), and F814W (I) broadband filters, and
the F658N (Hα) narrowband filter (GO program 10585; PI: Aloisi).
We had two different pointings in a rectangular shape along the major
axis of the galaxy.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 146 81 Cluster properties
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See also:
J/AJ/124/3157 : Velocities in NGC 4449 (Valdez-Gutierrez+, 2002)
J/AJ/141/113 : HII regions of M51 and NGC 4449 (Gutierrez+, 2011)
J/AZh/85/794 : UBVRHα photometry on 5 galaxies (Gusev+, 2008)
J/ApJ/741/86 : XRBs and star clusters in NGC 4449 (Rangelov+, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- ID [1/81] Cluster identification (8)
5- 14 A10 --- n_ID Notes (1)
16- 17 I2 h RAh Hour of Right Ascension (J2000)
19- 20 I2 min RAm Minute of Right Ascension (J2000)
22- 26 F5.2 s RAs Second of Right Ascension (J2000)
27 A1 --- DE- Sign of Declination (J2000)
28- 29 I2 deg DEd Degree of Declination (J2000)
31- 32 I2 arcmin DEm Arcminute of Declination (J2000)
34- 38 F5.2 arcsec DEs Arcsecond of Declination (J2000)
40- 43 F4.2 arcsec ReA Intrinsic angular effective radius (2)
45- 47 F3.1 pc ReP Intrinsic Linear effective radius (3)
49- 52 F4.2 --- ell Cluster ellipticity (4)
54- 58 F5.2 mag F435W HST/ACS F435W band Vega magnitude
60- 63 F4.2 mag e_F435W Uncertainty in F435W
65- 69 F5.2 mag F555W HST/ACS F555W band Vega magnitude
71- 74 F4.2 mag e_F555W Uncertainty in F555W
76- 80 F5.2 mag F814W HST/ACS F814W band Vega magnitude
82- 85 F4.2 mag e_F814W Uncertainty in F814W
87- 92 F6.2 mag VMAG Absolute Johnson-Cousins V magnitude (5)
94- 97 F4.2 mag e_VMAG Uncertainty in VMAG
99-103 I5 Myr Age ? Cluster age (6)
105-108 I4 Myr e_Age ? Lower uncertainty limit in Age
110-113 I4 Myr E_Age ? Upper uncertainty limit in Age
115-119 F5.2 10+5Msun Mass ? Cluster mass (6)
121-124 F4.2 10+5Msun e_Mass ? Lower uncertainty limit in Mass
126-129 F4.2 10+5Msun E_Mass ? Upper uncertainty limit in Mass
131-136 F6.2 mag VMAG10 ? Cluster absolute V magnitude at 10Myr (7)
138-141 F4.2 mag e_VMAG10 ? Lower uncertainty limit in VMAG10
143-146 F4.2 mag E_VMAG10 ? Upper uncertainty limit in VMAG10
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Note (1): Flags as:
* = clusters in common with Gelatt et al. (2001PASP..113..142G 2001PASP..113..142G), followed
by their ID assigned in Table 3 (<[GHG2001] NN> in Simbad).
d = clusters with B-V>0, V-I<0 (see Section 4.2).
s = clusters associated with Hα emission as shown in Fig. 3.
Note (2): Derived with ISHAPE (see Section 3.2).
Note (3): Derived from the angular effective radius adopting a distance of
3.82Mpc from Annibal et al. (2008AJ....135.1900A 2008AJ....135.1900A).
Note (4): Computed as 1-η, where η is the ISHAPE minor over major
axis ratio (see Section 3.2).
Note (5): Computed adopting a distance of 3.82Mpc from A08 Annibal et al.
2008AJ....135.1900A 2008AJ....135.1900A) and correcting for a Galactic reddening of
E(B-V)=0.019 (see Section 3.3). A reddening correction of E(B-V)=0.3
was applied to cluster 51 (see Section 4.2).
Note (6): Derived with the Z=0.004 Padova models (Girardi et al.,
2010ApJ...724.1030G 2010ApJ...724.1030G) and assuming a Salpeters' IMF down to 0.1M☉.
Clusters with "d" were fitted using the Z=0.004 GALEV models (see
Section 4.2). Only Galactic reddening was assumed, with the exception of
cluster 51, for which we solved for reddening and derived E(B-V)∼0.3.
Note (7): Obtained with the Z=0.004 Padova models (see Section 4.4), and with
the Z=0.004 GALEV models for clusters having a "d" note (n_ID=d).
Note (8): clusters named <[ATA2011] NN> in Simbad. The first line of
the table (superclustrer "SSC" at 12:28:11.13+44:05:37.42) without
photometry is not in this electronic version of the table.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 18-Jan-2013