2009A&A...497...41C


Query : 2009A&A...497...41C

2009A&A...497...41C - Astronomy and Astrophysics, volume 497, 41-51 (2009/4-1)

Early-type galaxies in the near-infrared: 1.5-2.4 µm spectroscopy.

CESETTI M., IVANOV V.D., MORELLI L., PIZZELLA A., BUSON L., CORSINI E.M., DALLA BONTA E., STIAVELLI M. and BERTOLA F.

Abstract (from CDS):

Near-infrared (hereafter NIR) data may provide complementary information to the traditional optical population synthesis analysis of unresolved stellar populations because the spectral energy distribution of the galaxies in the 1-2.5µm range is dominated by different types of stars than at optical wavelengths. Furthermore, NIR data are less affected by dust absorption and hence could constrain the stellar populations in dust-obscured galaxies. We attempt to develop observational constraints on the stellar populations of unresolved stellar systems in the NIR. To achieve this goal, we require benchmark NIR spectra of ``simple'' early-type galaxies, to test and calibrate the outputs of population synthesis models. We obtained low-resolution (R∼1000) long-slit spectra between 1.5 and 2.4µm for 14 nearby early-type galaxies using SofI at the ESO 3.5-m New Technology Telescope and higher resolution (R∼3000) long-slit spectra, centered on MgI at ∼1.51µm for a heterogeneous sample of 5 nearby galaxies observed with ISAAC at Antu, one of the 8.2-m ESO Very Large Telescope. We defined spectral indices corresponding to CO, NaI, CaI and MgI absorption lines and measured their strengths in the galaxies spectrum. We defined a new global NIR metallicity index, suitable for abundance measurements in low-resolution spectra. Finally, we created an average-combined NIR spectrum of an early-type galaxy, from a homogeneous subset of our data set. The NIR galaxy spectra are similar to each other and some of the line index strengths correlate with both the iron abundance [Fe/H] and optical metal line indices of the galaxies. The data suggest that the NIR metal features, in combination with a hydrogen absorption feature, may break the age-metallicity degeneracy in a similar way the Mg and Fe features in the rest-frame optical wavelength range.

Abstract Copyright:

Journal keyword(s): infrared: galaxies - Galaxy: abundances - galaxies: elliptical and lenticular, cD - galaxies: spiral - galaxies: stellar content

VizieR on-line data: <Available at CDS (J/A+A/497/41): table5.dat>

Simbad objects: 22

goto Full paper

goto View the references in ADS

Number of rows : 22
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024
#notes
1 Mrk 1055 AGN 02 48 18.5587681128 -08 57 37.712216556   15.74 15.19     ~ 29 0
2 NGC 1142 Sy2 02 55 12.2311509144 -00 11 00.807149472   15.42 14.41     ~ 330 1
3 NGC 1362 GiG 03 33 53.0769958488 -20 16 57.002480544   13.53   12.44   ~ 39 0
4 ACO S 373 ClG 03 38 29.4 -35 27 08           ~ 1831 0
5 NGC 3641 GiG 11 21 08.8111086864 +03 11 40.530956028   14.10 13.20     ~ 107 1
6 NGC 3818 EmG 11 41 57.3563891040 -06 09 20.459153376   13   11.78   ~ 179 0
7 NGC 4281 GiG 12 20 21.5246429784 +05 23 11.188759092   12.5       ~ 186 0
8 M 49 Sy2 12 29 46.8 +08 00 01   13.21 12.17     ~ 2097 2
9 NGC 4478 GiP 12 30 17.4160005576 +12 19 42.790577160 12.82 12.36 11.45   10.17 ~ 491 1
10 NGC 4564 GiG 12 36 26.9869512504 +11 26 21.204472848 12.51 12.05 11.12     ~ 596 1
11 M 104 LIN 12 39 59.43185902 -11 37 22.9961800 9.51 9.55 8.00 8.05   ~ 1399 3
12 M 59 GiG 12 42 02.2581375168 +11 38 48.909507756   11.0       ~ 696 0
13 NGC 4647 H2G 12 43 32.542 +11 34 56.89   12.5 12.5     ~ 408 0
14 M 60 GiP 12 43 39.9680 +11 33 09.696   10.3       ~ 1349 1
15 NGC 4697 GiG 12 48 35.8981498824 -05 48 02.482374564   10.97   9.83   ~ 862 0
16 NGC 5077 AGN 13 19 31.66962921 -12 39 25.0765176   13.87 12.85 11.30   ~ 296 0
17 IC 4296 rG 13 36 39.03253319 -33 57 57.0730368   11.52 12.99 10.00 10.79 ~ 495 2
18 NGC 5576 GiP 14 21 03.691 +03 16 15.78 12.25 11.85 10.96     ~ 330 1
19 NGC 6909 AG? 20 27 38.9325072768 -47 01 37.164117144   12.76 11.88 11.52   ~ 108 0
20 NGC 7714 GiP 23 36 14.1257730600 +02 09 18.197422668   14.91 14.36     ~ 765 1
21 APG 284 PaG 23 36 19 +02 09.3   12.6       ~ 607 0
22 NAME Local Group GrG ~ ~           ~ 8415 0

To bookmark this query, right click on this link: simbad:objects in 2009A&A...497...41C and select 'bookmark this link' or equivalent in the popup menu