J/A+AS/130/251 Star Formation in Early-type galaxies (Longhetti+ 1998)
Star formation history of early-type galaxies in low density environments.
I. Nuclear line-strength indices.
Longhetti M., Rampazzo R., Bressan A., Chiosi C.
<Astron. Astrophys. Suppl. Ser. 130, 251 (1998)>
=1998A&AS..130..251L 1998A&AS..130..251L (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Spectroscopy
Keywords: galaxies: fundamental parameters -
galaxies: elliptical and lenticular - galaxies: interactions -
galaxies: evolution
Abstract:
The paper is the first of a series (Longhetti et al.,
1998A&AS..130..267L 1998A&AS..130..267L, 1998b (Paper III) in press) dedicated to the
study of the star formation history in early-type galaxies which show
fine structures and/or interaction signatures. It presents nuclear
line-strength indices for a sample composed of 21 shell galaxies, from
the Malin & Carter (1983ApJ...274..534M 1983ApJ...274..534M) southern survey, and 30
members of isolated interacting pairs, from the Reduzzi & Rampazzo
(1995ApL....30....1R 1995ApL....30....1R) catalogue, located in low density environments.
The spectral range covers 3700Å<λ<5700Å at 2.1ÅFWHM
resolution. We measure 16 red (λ>4200Å) indices defined by
the Lick Group. Measures have been transformed into the Lick-IDS
``standard'' system. The procedure has been tested on a set of 5
elliptical galaxies selected from the Gonzalez (1993, Ph.D. thesis)
sample.
We derive also three blue (λ<4200) indices, namely
{DELTA}(4000Å) defined by Hamilton (1985ApJ...297..371H 1985ApJ...297..371H), H+K(CaII)
and Hdelta/FeI defined by Rose (1984AJ.....89.1238R 1984AJ.....89.1238R,
1985AJ.....90.1927R 1985AJ.....90.1927R). Blue indices are correlated to the age of the
last starburst occurred in a galaxy (Leonardi & Rose,
1996AJ....111..182L 1996AJ....111..182L).
The indices determination, the estimate of the measurement errors and
the correction for the galaxies velocity dispersions are discussed in
detail.
In the Appendix A we present the indices for a set of hot stars
(T>10000K) which may be used for extending, toward high temperatures,
Worthey (1992, Ph.D. Thesis) fitting functions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 121 21 Parameter of 21 shell galaxies
table2.dat 127 30 Parameter of 30 pair galaxies
table5.dat 28 56 Observational parameters of the sample
table6.dat 79 16 Red indices adopted bandpasses
table8.dat 43 18 Parameters of the adopted stellar atlas
table9.dat 41 16 *Comparison between CCD measures and IDS data
table10.dat 52 18 Behaviour of the indices as a function of
velocity dispersion
table11.dat 43 95 Indices for the template galaxies and
comparisons with Worthey 98 data
table12.dat 41 570 Indices for the pair galaxies sample
table13.dat 41 418 Indices for the shell galaxies
table14.dat 52 17 Parameters of the adopted hot stars sample
table15.dat 155 8 *Extension of the Lick Fitting Functions
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Note on table9.dat: Comparison between CCD measures (from this paper and
from Gonzalez (1993, Ph.D. Thesis)) and IDS data.
Note on table15.dat: Coefficients for the extension of the standard fitting
functions of indices (Worthey, 1992, Ph.D. Thesis) to the high temperature
regime (T_eff>10000K)
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See also:
VII/115 : Surface Photometry of the ESO-Uppsala Galaxies (ESO-LV, 1989)
J/other/ApL/30.1 : Isolated pairs southern catalogue extension (Reduzzi+ 1995)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name ESO (Cat. VII/34) galaxy designation (1)
13- 19 A7 --- OtherName ? Other object identification
21- 22 I2 h RAh Right ascension (1950)
24- 25 I2 min RAm Right ascension (1950)
27- 28 I2 s RAs Right ascension (1950)
30 A1 --- DE- ? Declination sign
31- 32 I2 deg DEd Declination (1950)
34- 35 I2 arcmin DEm Declination (1950)
37- 38 I2 arcsec DEs Declination (1950)
40- 43 F4.1 mag Bmag Total B magnitude
45- 48 F4.1 --- T Morphological type
50- 54 F5.2 mag/arcsec+2 SuBr Surface brightness mu(e) in B band
56- 60 F5.1 arcsec A(e) Effective aperture in B band
62- 68 F7.4 mag E(B-V) Extinction coefficient
70- 74 I5 km/s V0 ? Recession velocity
76- 98 A23 --- Com Fine structures description
100-121 A22 --- Envir Density environment (2)
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Note (1): ESO name: ESO NNNMMMd = ESO NNN-MMMa (or ESO-LV NNN-MMMd)
in Simbad, where a is blank for d=0, a=A for d=1, a=B for d=2, etc.
Note (2): I stands for isolated galaxies
G stands for galaxies in group
C stands for galaxies in clusters
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name ESO (Cat. VII/34) galaxy designation
13- 19 A7 --- OtherName ? Other object identification
21- 26 A6 --- RR95 Object ident. in the RR95
(1995ApL....30....1R 1995ApL....30....1R) catalogue
28- 29 I2 h RAh Right Ascension (1950)
31- 32 I2 min RAm Right Ascension (1950)
34- 35 I2 s RAs Right Ascension (1950)
37 A1 --- DE- ? Declination sign
38- 39 I2 deg DEd Declination (1950)
41- 42 I2 arcmin DEm Declination (1950)
44- 45 I2 arcsec DEs Declination (1950)
47- 50 F4.1 mag Bmag Total B magnitude
52- 55 F4.1 --- T Morphological Type
57- 61 F5.2 mag SuBr Surface brightness mu(e) in B band
63- 67 F5.1 arcsec A(e) Effective aperture (B)
69- 75 F7.4 --- E(B-V) Extinction coefficient
77- 80 F4.1 arcsec Sep Angular separation
82- 85 I4 km/s V0 ? Recession velocity
87- 89 I3 km/s DV ? Separation in the velocity field
91-125 A35 --- Com Fine structures description
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Table 3: Template galaxies
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Name RA (2000) DE BT T E(B-V) V0
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NGC 584 01 31 21 -06 52 06 11.4 -5.0 0.030 1864
NGC 7562 23 15 57 +06 41 15 12.6 -5.0 0.050 3636
NGC 7619 23 20 15 +08 12 23 12.1 -5.0 0.040 3804
NGC 7626 23 20 42 +08 13 02 12.2 -5.0 0.040 3423
NGC 7785 23 55 19 +05 54 43 12.6 -5.0 0.040 3849
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Table 4: Observing parameters
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Run 1 Run 2 Run 3
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Date of observations 7-9 March 1-5 August 14-21 August
Observer Longhetti, M. Bonfanti, P. Longhetti, M.
Spectral range [Å] 3750-5750 3704-5710 3728-5747
Seeing (FWHM)[arcsec] 1.0 - 1.5 1.0 - 1.5 < 2
Parameters for all the runs
Spectrograph = Boller & Chivens
Detector = Fa 2048 L
Pixel size = 15 µm2
Scale along the slit = 0.61 "/pix
Slit length = 4.2 arcmin
Slit width = 2.0 arcsec
Dispersion = 66 Å/mm
Spectral resolution (FWHM at 5200{AA) = 2.1
Instrumental velocity dispersion sigma = 51 km/s
Standard stars spectral type = K0-K2 III
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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- 11 A11 --- Name Object identification
13 I1 --- Run Observational run identification
15- 17 I3 deg PA Position angle of the slit (N to E)
19- 21 I3 min Texp Exposition time
23 I1 --- S/N Signal to Noise class (1)
25- 28 F4.2 --- D5 ? 5arcsec/Diameter
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Note (1): The spectrum quality is defined as the average S/N ratio in the
wavelength range 4000-5000Å. Higher S/N spectra are indicated
with 3 (S/N>20) while lower ones are indicated with 1 (S/N≤10).
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- IndexId Index identification
8- 23 A16 --- Features Spectral features related to the index
25- 32 F8.3 0.1nm I1 Bluer limit of the feature bandpass
34- 41 F8.3 0.1nm I2 Redder limit of the feature bandpass
43- 50 F8.3 0.1nm B1 Bluer limit of the blue continuum bandpass
52- 59 F8.3 0.1nm B2 Redder limit of the blue continuum bandpass
61- 68 F8.3 0.1nm R1 Bluer limit of the red continuum bandpass
70- 77 F8.3 0.1nm R2 Redder limit of the red continuum bandpass
79 A1 --- Type [MA] Index type (1)
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Note (1): M: molecular indices
A: atomic indices
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Table 7: Definition of the "blue" indices
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Index Spectral feature lambda1-lambda2 lambda3-lambda4 lambda5-lambda6
[0.1nm] [0.1nm] [0.1nm]
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H+K(CaII) H K (CaII), Heps 3926.0-3940.0 3961.0-3975.0
Hdelta/FeI Hdelta, FeI 4095.0-4108.0 4041.0-4050.0 4055.0-4070.0
Delta(4000AA) 4000AA break 3750.0-3950.0 4050.0-4250.0
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- HR ? HR number identification
6- 11 I6 --- HD HD number identification
13- 16 F4.2 mag Vmag ? V magnitude
18- 21 F4.2 mag B-V ? (B-V) colour
23- 26 F4.2 mag U-B ? (U-B) colour
28- 31 F4.2 mag R-I ? (R-I) colour
33- 39 A7 --- SpType Spectral class
41- 43 I3 km/s RV ? Radial velocity
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- IndexId Index identification
8 A1 --- Type [MA] Index type (1)
10- 15 F6.3 --- Diff Mean difference IDS-CCD measures
17- 21 F5.1 % Diff% Mean difference IDS-CCD measures in percents
23- 28 F6.3 --- Shift Adopted shift
30- 35 F6.3 --- DiffG93 Mean difference IDS-CCD(G93) measures (2)
37- 41 F5.3 --- ShiftG93 Shift adopted by G93 (2)
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Note (1): The units adopted for Diff, Shift, DiffG93 and ShiftG93 are
Angstroem or mag relative to the kind of index (atomic or molecular)
M: Molecular ⟹ mag
A: Atomic ⟹ Angstroem (0.1nm)
Note (2): G93 = Gonzalez 1993, PhD Thesis.
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- IndexId Index identification
12- 16 F5.3 --- I50/I0 Index ratio for σ= 50km/s (1)
18- 22 F5.3 --- I100/I0 Index ratio for σ= 100 km/s (1)
24- 28 F5.3 --- I125/I0 Index ratio for σ= 125 km/s (1)
30- 34 F5.3 --- I150/I0 Index ratio for σ= 150 km/s (1)
36- 40 F5.3 --- I200/I0 Index ratio for σ= 200 km/s (1)
42- 46 F5.3 --- I250/I0 Index ratio for σ= 250 km/s (1)
48- 52 F5.3 --- I300/I0 Index ratio for σ= 300 km/s (1)
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Note (1): All the numerical values represent the ratio between the index
value corresponding to the indicated velocity dispersion and that
corresponding to a null velocity dispersion.
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Byte-by-byte Description of file: table11.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Object identification
14- 23 A10 --- IndexId Index identification (1)
25- 29 F5.3 --- Index Index value (2)
31- 35 F5.3 --- e_Index rms uncertainty on Index (2)
37- 42 F6.3 --- dIndex ? our data - Worthey (1998) data (2)
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Note (1): D400A : delta (4000A break)
Note (2): The units are mag for CN, CN2 Mg1 and Mg2, Angstroem (0.1nm) else.
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Byte-by-byte Description of file: table13.dat table12.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Object identification
14- 23 A10 --- IndexId Index identification (1)
25- 32 F8.4 --- Index Index value (2)
34- 41 F8.4 --- e_Index rms uncertainty on Index (2)
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Note (1): D400A : delta (4000A break)
Note (2): The units are mag for CN, CN2 Mg1 and Mg2, Angstroem (0.1nm) else.
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Byte-by-byte Description of file: table14.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- HR ? HR number identification
9- 17 A9 --- HD HD number identification
19- 22 F4.2 mag Vmag V magnitude
24- 28 F5.2 mag B-V B-V colour index
30- 33 A4 --- SpType Spectral classification
35- 39 I5 K Teff Effective temperature
41- 43 F3.1 [cm/s+2] log(g) ? Log_10 of gravity
45- 48 F4.2 [Sun] [Fe/H] ? Metallicity
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Byte-by-byte Description of file: table15.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- g [-2/1] g parameter (1)
4 A1 --- Cn [0/1] Cn value (C0 or C1)
6- 13 F8.5 --- CN Coefficients for the index CN
15- 22 F8.5 --- CN2 Coefficients for the index CN2
24- 31 F8.5 --- Ca42 Coefficients for the index Ca4227
33- 41 F9.5 --- G4300 Coefficients for the index G4300
43- 51 F9.5 --- Fe43 Coefficients for the index Fe4383
53- 61 F9.5 --- Ca44 Coefficients for the index Ca4455
63- 71 F9.5 --- Fe45 Coefficients for the index Fe4531
73- 81 F9.5 --- Fe46 Coefficients for the index Fe4668
83- 91 F9.5 --- Hb Coefficients for the index Hbeta
93-101 F9.5 --- Fe50 Coefficients for the index Fe5015
103-110 F8.5 --- Mg1 Coefficients for the index Mg1
112-119 F8.5 --- Mg2 Coefficients for the index Mg2
121-128 F8.5 --- Mgb Coefficients for the index Mgb
130-137 F8.5 --- Fe52 Coefficients for the index Fe5270
139-146 F8.5 --- Fe53 Coefficients for the index Fe5335
148-155 F8.5 --- Fe54 Coefficients for the index Fe5406
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Note (1): The coefficients are related to a linear interpolation between
the indices values and the stellar temperatures:
I = C0 + C1*Log(Teff). Couples of rows report respectively
the C0 and C1 values for different values of the parameter
g, g=-2 (for the first couple of rows), g=-1, g=0 and g=1
(for the last couple of rows).
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Acknowledgements: Marcella Longhetti
History:
* 17-Jul-1998: the designations of the galaxies have been homogenized
between tables 1, 2, 5, 11, 12 and 13.
(End) Patricia Bauer [CDS] 26-Mar-1998