J/MNRAS/441/3570 Nuclear star clusters in 228 spiral galaxies (Georgiev+, 2014)
Nuclear star clusters in 228 spiral galaxies in the HST/WFPC2 archive: catalogue
and comparison to other stellar systems.
Georgiev I.Y., Boker T.
<Mon. Not. R. Astron. Soc., 441, 3570-3590 (2014)>
=2014MNRAS.441.3570G 2014MNRAS.441.3570G
ADC_Keywords: Galaxy catalogs ; Photometry, HST ; Morphology
Keywords: galaxies: spiral - galaxies: star clusters: general
Abstract:
We present a catalogue of photometric and structural properties of 228
nuclear star clusters (NSCs) in nearby late-type disc galaxies. These
new measurements are derived from a homogeneous analysis of all
suitable Wide Field Planetary Camera 2 (WFPC2) images in the
Hubble Space Telescope (HST) archive. The luminosity and size
of each NSC are derived from an iterative point spread function (PSF)
fitting technique, which adapts the fitting area to the effective
radius (reff) of the NSC and uses a WFPC2-specific PSF model
tailored to the position of each NSC on the detector. The luminosities
of NSCs are ≤108LV,☉, and their integrated optical colours
suggest a wide spread in age. We confirm that most NSCs have sizes
similar to globular clusters (GCs), but find that the largest and
brightest NSCs occupy the regime between ultra-compact dwarf (UCD) and
the nuclei of early-type galaxies in the size-luminosity plane. The
overlap in size, mass, and colour between the different incarnations
of compact stellar systems provides a support for the notion that at
least some UCDs and the most massive Galactic GCs may be remnant
nuclei of disrupted disc galaxies. We find tentative evidence for the
NSCs' reff to be smaller when measured in bluer filters and
discuss possible implications of this result. We also highlight a few
examples of complex nuclear morphologies, including double nuclei,
extended stellar structures, and nuclear F606W excess from
either recent (circum-)nuclear star formation and/or a weak active
galactic nucleus. Such examples may serve as case studies for ongoing
NSC evolution via the two main suggested mechanisms, namely cluster
merging and in situ star formation.
Description:
We searched the HST/WFPC2 archive for all exposures of galaxies with
late Hubble type (t≥3.5) to avoid the most luminous bulges, an
inclination of i≤88° to avoid edge-on galaxies, and distances of
≤40Mpc, (m-M)≲33mag to be able to reliably measure the size of the
Nuclear Star Clusters.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 103 228 Main properties of the galaxy sample with
measured NSC (Nuclear Star Cluster) properties
table2.dat 163 95 Main properties of the galaxy sample without an
identifiable (Nuclear Star Cluster) NSC
table3.dat 311 228 Effective radius measurements of NSCs
table4.dat 308 228 Ellipticities and position angles of the NSCs
in our sample
table5.dat 161 228 NSC photometry
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Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Galaxy name
16- 17 I2 h RAh Right ascension (J2000) from HyperLeda
19- 20 I2 min RAm Right ascension (J2000) from HyperLeda
22- 26 F5.2 s RAs Right ascension (J2000) from HyperLeda
28 A1 --- DE- Declination sign (J2000) from HyperLeda
29- 30 I2 deg DEd Declination (J2000) from HyperLeda
32- 33 I2 arcmin DEm Declination (J2000) from HyperLeda
35- 39 F5.2 arcsec DEs Declination (J2000) from HyperLeda
41- 45 F5.2 mag MOD [23/38] Median distance modulus (1)
47- 51 F5.3 mag E(B-V) [0/0.9] Median colour excess (1)
53- 57 F5.2 mag Bmag Total B magnitude from HyperLeda
59- 62 F4.2 mag B-V ?=- Total B-V colour index from HyperLeda
64- 68 F5.2 mag Imag ?=- Total I magnitude from HyperLeda
70- 76 F7.4 kpc R25 ?=- Radius at the isophote
25B-mag/arcsec2 from HyperLeda
78- 81 F4.2 --- Ell [0/1]?=- Ellipticity from HyperLeda
83- 87 F5.1 deg PA [0/180]? Position angle from HyperLeda
89- 92 F4.1 deg i [0/90]?=- Inclination from HyperLeda
94- 97 A4 --- Type Morphological type from HyperLeda
99-102 F4.1 --- t [3.5/10]?=- Morphological code from HyperLeda
104-163 A60 --- Com Comments (only in table2) (2)
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Note (1): Taken from NED. More specifically, the distance modulus is the median
value in NED. If the latter is not available, we adopt the redshift-derived
distance modulus, modz, from HyperLeda.
Note (2): identifies the reason why the galaxy was unsuitable for an NSC
measurement, together with the filter and (with subscript) the WFPC2
detector of the exposure(s).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Galaxy name
15- 19 F5.1 pc re1 ?=- Effective radius at F606W
21- 24 F4.1 pc e_re1 ?=- Error on re1 (lower value)
26- 28 F3.1 pc E_re1 ?=- Error on re1 (upper value)
31- 38 A8 --- S1 Shape index at F606W (3)
40 I1 --- D1 [1/4]?=- Detector at F606W
42- 46 F5.1 --- S/N1 [2.4/1300]?=- Signal-to-noise ration at F606W
48- 52 F5.1 pc re2 ?=- Effective radius at F814W
54- 57 F4.1 pc e_re2 ?=- Error on re2 (lower value)
59- 61 F3.1 pc E_re2 ?=- Error on re2 (upper value)
64- 71 A8 --- S2 Shape index at F814W (3)
74 I1 --- D2 [1/4]?=- Detector at F814W
76- 81 F6.1 --- S/N2 [2.4/1300]?=- Signal-to-noise ration at F814W
84- 88 F5.1 pc re3 ?=- Effective radius at F450W
90- 93 F4.1 pc e_re3 ?=- Error on re3 (lower value)
95- 97 F3.1 pc E_re3 ?=- Error on re3 (upper value)
100-107 A8 --- S3 Shape index at F450W (3)
109 I1 --- D3 [1/4]?=- Detector at F450W
112-116 F5.1 --- S/N3 [2.4/1300]?=- Signal-to-noise ration at F450W
119-122 F4.1 pc re4 ?=- Effective radius at F555W
124-126 F3.1 pc e_re4 ?=- Error on re4 (lower value)
128-130 F3.1 pc E_re4 ?=- Error on re4 (upper value)
133-140 A8 --- S4 Shape index at F555W (3)
142 I1 --- D4 [1/4]?=- Detector at F555W
144-148 F5.1 --- S/N4 [2.4/1300]?=- Signal-to-noise ration at F555W
150-154 F5.1 pc re5 ?=- Effective radius at F300W
156-159 F4.1 pc e_re5 ?=- Error on re6 (lower value)
161-163 F3.1 pc E_re5 ?=- Error on re6 (upper value)
165-173 A9 --- S5 Shape index at F300W (3)
176 I1 --- D5 [1/4]?=- Detector at F300W
178-182 F5.1 --- S/N5 [2.4/1300]?=- Signal-to-noise ration at F300W
184-187 F4.1 pc re6 ?=- Effective radius at F439W
189-192 F4.1 pc e_re6 ?=- Error on re7 (lower value)
194-196 F3.1 pc E_re6 ?=- Error on re7 (upper value)
199-206 A8 --- S6 Shape index at F439W (3)
208 I1 --- D6 [1/4]?=- Detector at F439W
210-214 F5.1 --- S/N6 [2.4/1300]?=- Signal-to-noise ration at F439W
216-220 F5.1 pc re7 ?=- Effective radius at F336W
222-225 F4.1 pc e_re7 ?=- Error on re8 (lower value)
227-230 F4.1 pc E_re7 ?=- Error on re8 (upper value)
233-240 A8 --- S7 Shape index at F336W (3)
242 I1 --- D7 [1/4]?=- Detector at F336W
244-248 F5.1 --- S/N7 [2.4/1300]?=- Signal-to-noise ration at F336W
250-252 F3.1 pc re8 ?=- Effective radius at F380W
254-256 F3.1 pc e_re8 ?=- Error on re9 (lower value)
258-260 F3.1 pc E_re8 ?=- Error on re9 (upper value)
263-270 A8 --- S8 Shape index at F380W (3)
272 I1 --- D8 [1/4]?=- Detector at F380W
274-278 F5.1 --- S/N8 [2.4/1300]?=- Signal-to-noise ration at F380W
281-284 F4.1 pc re9 ?=- Effective radius at F675W
286-289 F4.1 pc e_re9 ?=- Error on re10 (lower value)
291-293 F3.1 pc E_re9 ?=- Error on re10 (upper value)
295-302 A8 --- S9 Shape index at F675W (3)
305 I1 --- D9 [1/4]?=- Detector at F675W
307-311 F5.1 --- S/N9 [2.4/1300]?=- Signal-to-noise ration at F675W
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Note (3): the shape of the nuclear cluster is one of:
* King profile (tidally truncated isothermal sphere); see
King 1962AJ.....67..471K 1962AJ.....67..471K, 1966AJ.....71...64K 1966AJ.....71...64K, followed by a
concentration index C=rtidal/rcore (5, 15, 30 or 100)
* EFF profile (power-law, see Elson et al. 1987ApJ...323...54E 1987ApJ...323...54E),
followed by the index of the power-law (1.5 or 2.5)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Name
15- 18 F4.2 --- e1 [0/1]?=- Ellipticity from F606W measurement
21- 24 F4.2 --- e_e1 [0/1]?=- Error on e1 (lower value)
26- 29 F4.2 --- E_e1 [0/1]?=- Error on e1 (upper value)
31- 35 F5.1 deg pa1 [0/180]?=- Position angle from F606W measurement
38- 41 F4.1 deg e_pa1 [0/90]?=- Error on pa1 (lower value)
43- 46 F4.1 deg E_pa1 [0/90]?=- Error on pa1 (upper value)
48- 51 F4.2 --- e2 [0/1]?=- Ellipticity from F814W measurement
54- 57 F4.2 --- e_e2 [0/1]?=- Error on e2 (lower value)
59- 62 F4.2 --- E_e2 [0/1]?=- Error on e2 (upper value)
64- 68 F5.1 deg pa2 [0/180]?=- Position angle from F814W measurement
71- 74 F4.1 deg e_pa2 [0/90]?=- Error on pa2 (lower value)
76- 79 F4.1 deg E_pa2 [0/90]?=- Error on pa2 (upper value)
81- 84 F4.2 --- e3 [0/1]?=- Ellipticity from F450W measurement
87- 90 F4.2 -- e_e3 [0/1]?=- Error on e3 (lower value)
92- 95 F4.2 --- E_e3 [0/5]?=- Error on e3 (upper value)
97-101 F5.1 deg pa3 [0/180]?=- Position angle from F450W measurement
104-107 F4.1 deg e_pa3 [0/90]?=- Error on pa3 (lower value)
109-112 F4.1 deg E_pa3 [0/90]?=- Error on pa3 (upper value)
114-117 F4.2 --- e4 [0/1]?=- Ellipticity from F555W measurement
120-123 F4.2 --- e_e4 [0/1]?=- Error on e4 (lower value)
125-128 F4.2 --- E_e4 [0/1]?=- Error on e4 (upper value)
130-134 F5.1 deg pa4 [0/180]?=- Position angle from F555W measurement
137-140 F4.1 deg e_pa4 [0/90]?=- Error on pa4 (lower value)
142-145 F4.1 deg E_pa4 [0/90]?=- Error on pa4 (upper value)
147-150 F4.2 --- e5 [0/1]?=- Ellipticity from F300W measurement
154-157 F4.2 --- e_e5 [0/1]?=- Error on e5 (lower value)
159-162 F4.2 --- E_e5 [0/4]?=- Error on e5 (upper value)
164-168 F5.1 deg pa5 [0/180]?=- Position angle from F300W measurement
171-174 F4.1 deg e_pa5 [0/90]?=- Error on pa5 (lower value)
176-179 F4.1 deg E_pa5 [0/90]?=- Error on pa5 (upper value)
181-184 F4.2 --- e6 [0/1]?=- Ellipticity from F439W measurement
187-190 F4.2 --- e_e6 [0/1]?=- Error on e6 (lower value)
192-195 F4.2 --- E_e6 [0/1]?=- Error on e6 (upper value)
197-201 F5.1 deg pa6 [0/180]?=- Position angle from F439W measurement
204-207 F4.1 deg e_pa6 [0/90]?=- Error on pa6 (lower value)
209-211 F3.1 deg E_pa6 [0/90]?=- Error on pa6 (upper value)
213-216 F4.2 --- e7 [0/1]?=- Ellipticity from F336W measurement
219-222 F4.2 --- e_e7 [0/1]?=- Error on e7 (lower value)
224-227 F4.2 --- E_e7 [0/1]?=- Error on e7 (upper value)
229-233 F5.1 deg pa7 [0/180]?=- Position angle from F336W measurement
236-239 F4.1 deg e_pa7 [0/90]?=- Error on pa7 (lower value)
241-244 F4.1 deg E_pa7 [0/90]?=- Error on pa7 (upper value)
246-249 F4.2 --- e8 [0/1]?=- Ellipticity from F380W measurement
253-256 F4.2 --- e_e8 [0/1]?=- Error on e8 (lower value)
258-261 F4.2 --- E_e8 [0/1]?=- Error on e8 (upper value)
263-266 F4.1 deg pa8 [0/180]?=- Position angle from F380W measurement
269-271 F3.1 deg e_pa8 [0/90]?=- Error on pa8 (lower value)
273-275 F3.1 deg E_pa8 [0/90]?=- Error on pa8 (upper value)
277-280 F4.2 --- e9 [0/1]?=- Ellipticity from F675W measurement
283-286 F4.2 --- e_e9 [0/1]?=- Error on e9 (lower value)
288-291 F4.2 --- E_e9 [0/1]?=- Error on e9 (upper value)
293-297 F5.1 deg pa9 [0/180]?=- Position angle from F675W measurement
300-303 F4.1 deg e_pa9 [0/90]?=- Error on pa9 (lower value)
305-308 F4.1 deg E_pa9 [0/90]?=- Error on pa9 (upper value)
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Name
15- 16 I2 h RAp.h Right ascension (J2000) of photometry
18- 19 I2 min RAp.m Right ascension (J2000) of photometry
21- 25 F5.2 s RAp.s Right ascension (J2000) of photometry
27 A1 --- DEp.- Declination sign (J2000) of photometry
28- 29 I2 deg DEp.d Declination (J2000) of photometry
31- 32 I2 arcmin DEp.m Declination (J2000) of photometry
34- 38 F5.2 arcsec DEp.s Declination (J2000) of photometry
40- 44 F5.3 mag E(B-V) ?=- Redenning
46- 50 F5.2 mag m1 ?=- Deredenned F606W magnitude (4)
52- 55 F4.2 mag e_m1 ?=- rms uncertainty on F606W
57 I1 --- D1 [1/4]?=- Detector used for F606W
59- 63 F5.2 mag m2 ?=- Deredenned F814W magnitude (4)
65- 68 F4.2 mag e_m2 ?=- rms uncertainty on F814W
70 I1 --- D2 [1/4]?=- Detector used for F814W
72- 76 F5.2 mag m3 ?=- Deredenned F450W magnitude (4)
78- 81 F4.2 mag e_m3 ?=- rms uncertainty on F450W
83 I1 --- D3 [1/4]?=- Detector used for F450W
85- 89 F5.2 mag m4 ?=- Deredenned F555W magnitude (4)
91- 94 F4.2 mag e_m4 ?=- rms uncertainty on F555W
96 I1 --- D4 [1/4]?=- Detector used for F555W
98-102 F5.2 mag m9 ?=- Deredenned F675W magnitude (4)
104-107 F4.2 mag e_m9 ?=- rms uncertainty on F675W
109 I1 --- D9 [1/4]?=- Detector used for F675W
111-115 F5.2 mag m5 ?=- Deredenned F300W magnitude (4)
117-120 F4.2 mag e_m5 ?=- rms uncertainty on F300W
122 I1 --- D5 [1/4]?=- Detector used for F300W
124-128 F5.2 mag m7 ?=- Deredenned F336W magnitude (4)
130-133 F4.2 mag e_m7 ?=- rms uncertainty on F336W
135 I1 --- D7 [1/4]?=- Detector used for F336W
137-141 F5.2 mag m8 ?=- Deredenned F380W magnitude (4)
143-146 F4.2 mag e_m8 ?=- rms uncertainty on F380W
148 I1 --- D8 [1/4]?=- Detector used for F380W
150-154 F5.2 mag m6 ?=- Deredenned F439W magnitude (4)
156-159 F4.2 mag e_m6 ?=- rms uncertainty on F439W
161 I1 --- D6 [1/4]?=- Detector used for F439W
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Note (4): charge transfer efficiency- and Galactic foreground
reddening-corrected magnitude in the WFPC2 photometric system.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 12-Feb-2015