27 research outputs found
Redshift-Distance Survey of Early-type Galaxies. I. Sample Selection, Properties and Completeness
This is the first in a series of papers describing the recently completed
all-sky redshift-distance survey of nearby early-type galaxies (ENEAR) carried
out for peculiar velocity analysis. The sample is divided into two parts and
consists of 1607 elliptical and lenticular galaxies with cz < 7000 km/s and
with blue magnitudes brighter than m_B=14.5 (ENEARm), and of galaxies in
clusters (ENEARc). Galaxy distances based on the Dn-sigma and Fundamental Plane
(FP) relations are now available for 1359 and 1107 ENEARm galaxies,
respectively, with roughly 80% based on new data gathered by our group. The
Dn-sigma and FP template distance relations are derived by combining 569 and
431 galaxies in 28 clusters, respectively, of which about 60% are based on our
new measurements. The ENEARm redshift-distance survey extends the earlier work
of the 7S and the recent Tully-Fisher surveys sampling a comparable volume. In
subsequent papers of this series we intend to use the ENEAR sample by itself or
in combination with the SFI Tully-Fisher survey to analyze the properties of
the local peculiar velocity field and to test how sensitive the results are to
different sampling and to the distance indicators. We also anticipate that the
homogeneous database assembled will be used for a variety of other applications
and serve as a benchmark for similar studies at high-redshift.Comment: 43 pages, 15 figures, submitted to the Astronomical Journa
ESO Imaging Survey: infrared observations of CDF-S and HDF-S
This paper presents infrared data obtained from observations carried out at
the ESO 3.5m New Technology Telescope (NTT) of the Hubble Deep Field South
(HDF-S) and the Chandra Deep Field South (CDF-S). These data were taken as part
of the ESO Imaging Survey (EIS) program, a public survey conducted by ESO to
promote follow-up observations with the VLT. In the HDF-S field the infrared
observations cover an area of ~53 square arcmin, encompassing the HST WFPC2 and
STIS fields, in the JHKs passbands. The seeing measured in the final stacked
images ranges from 0.79" to 1.22" and the median limiting magnitudes (AB
system, 2" aperture, 5sigma detection limit) are J_AB~23.0, H_AB~22.8 and
K_AB~23.0 mag. Less complete data are also available in JKs for the adjacent
HST NICMOS field. For CDF-S, the infrared observations cover a total area of
\~100 square arcmin, reaching median limiting magnitudes (as defined above) of
J_AB~23.6 and K_AB~22.7 mag. For one CDF-S field H-band data are also
available. This paper describes the observations and presents the results of
new reductions carried out entirely through the un-supervised, high-throughput
EIS Data Reduction System and its associated EIS/MVM C++-based image processing
library developed, over the past 5 years, by the EIS project and now publicly
available. The paper also presents source catalogs extracted from the final
co-added images which are used to evaluate the scientific quality of the survey
products, and hence the performance of the software. This is done comparing the
results obtained in the present work with those obtained by other authors from
independent data and/or reductions carried out with different software packages
and techniques. The final science-grade catalogs and co-added images are
available at CDS.Comment: Accepted for publication in A&A, 13 pages, 12 figures; a full
resolution version of the paper is available from
http://www.astro.ku.dk/~lisbeth/eisdata/papers/4528.pdf ; related catalogs
and images are available through http://www.astro.ku.dk/~lisbeth/eisdata
Redshift-distance Survey of Early-type Galaxies: The D_n-sigma Relation
In this paper R-band photometric and velocity dispersion measurements for a
sample of 452 elliptical and S0 galaxies in 28 clusters are used to construct a
template D_n-sigma relation. This template relation is constructed by combining
the data from the 28 clusters, under the assumption that galaxies in different
clusters have similar properties. The photometric and spectroscopic data used
consist of new as well as published measurements, converted to a common system,
as presented in a accompanying paper. The resulting direct relation, corrected
for incompleteness bias, is log{D_n} =1.203 log{sigma} + 1.406; the zero-point
has been defined by requiring distant clusters to be at rest relative to the
CMB. This zero-point is consistent with the value obtained by using the
distance to Virgo as determined by the Cepheid period-luminosity relation. This
new D_n-sigma relation leads to a peculiar velocity of -72 (\pm 189) km/s for
the Coma cluster. The scatter in the distance relation corresponds to a
distance error of about 20%, comparable to the values obtained for the
Fundamental Plane relation. Correlations between the scatter and residuals of
the D_n-sigma relation with other parameters that characterize the cluster
and/or the galaxy stellar population are also analyzed. The direct and inverse
relations presented here have been used in recent studies of the peculiar
velocity field mapped by the ENEAR all-sky sample.Comment: 46 pages, 20 figures, and 7 tables. To appear in AJ, vol. 123, no. 5,
May 200
Cluster vs. Field Elliptical Galaxies and Clues on their Formation
Using new observations for a sample of 931 early-type galaxies we investigate
whether the \mg2--\so relation shows any dependence on the local environment.
The galaxies have been assigned to three different environments depending on
the local overdensity: clusters, groups, and field, having used our
completeredshift database to guide the assignment of galaxies. It is found that
cluster, group and field early-type galaxies follow almost identical \mg2--\so\
relations, with the largest \mg2 zero-point difference (clusters minus field)
being only mag. No correlation of the residuals is found with
the morphological type or the bulge to disk ratio. Using stellar population
models in a differential fashion, this small zero-point difference implies a
luminosity-weighted age difference of only Gyr between the
corresponding stellar populations, with field galaxies being younger. The
mass-weighted age difference could be significantly smaller, if minor events of
late star formation took place preferentially in field galaxies. We combine
these results with the existing evidence for the bulk of stars in cluster
early-type galaxies having formed at very high redshift, and conclude that the
bulk of stars in galactic spheroids had to form at high redshifts (z\gsim 3),
no matter whether such spheroids now reside in low or high density regions. The
cosmological implications of these findings are briefly discussed.Comment: 16 pages, 2 figures, accepted for publication in the ApJ.
ESO Imaging Survey: Optical follow-up of 12 selected XMM-Newton fields
(Abridged) This paper presents the data recently released for the
XMM-Newton/WFI survey carried out as part of the ESO Imaging Survey (EIS)
project. The aim of this survey is to provide optical imaging follow-up data in
BVRI for identification of serendipitously detected X-ray sources in selected
XMM-Newton fields. In this paper, fully calibrated individual and stacked
images of 12 fields as well as science-grade catalogs for the 8 fields located
at high-galactic latitude are presented. The data covers an area of \sim 3
square degrees for each of the four passbands. The median limiting magnitudes
(AB system, 2" aperture, 5\sigma detection limit) are 25.20, 24.92, 24.66, and
24.39 mag for B-, V-, R-, and I-band, respectively. These survey products,
together with their logs, are available to the community for science
exploitation in conjunction with their X-ray counterparts. Preliminary results
from the X-ray/optical cross-correlation analysis show that about 61% of the
detected X-ray point sources in deep XMM-Newton exposures have at least one
optical counterpart within 2" radius down to R \simeq 25 mag, 50% of which are
so faint as to require VLT observations thereby meeting one of the top
requirements of the survey, namely to produce large samples for spectroscopic
follow-up with the VLT, whereas only 15% of the objects have counterparts down
to the DSS limiting magnitude.Comment: 24 pages, 10 figures, accepted for publication in Astronomy and
Astrophysics. Accompanying data releases available at
http://archive.eso.org/archive/public_datasets.html (WFI images),
http://www.eso.org/science/eis/surveys/release_65000025_XMM.html (optical
catalogs), http://www.aip.de/groups/xray/XMM_EIS/ (X-ray data). Full
resolution version available at
http://www.astro.uni-bonn.de/~dietrich/publications/3785.ps.g
ESO Imaging Survey. The Stellar Catalogue in the Chandra Deep Field South
(abridged) Stellar catalogues in five passbands (UBVRI) over an area of
approximately 0.3 deg^2, comprising about 1200 objects, and in seven passbands
(UBVRIJK) over approximately 0.1 deg^2, comprising about 400 objects, in the
direction of the Chandra Deep Field South are presented.
The 90% completeness level of the number counts is reached at approximately U
= 23.8, B = 24.0, V = 23.5, R = 23.0, I = 21.0, J = 20.5, K = 19.0.
A scheme is presented to select point sources from these catalogues, by
combining the SExtractor parameter CLASS_STAR from all available passbands.
Probable QSOs and unresolved galaxies are identified by using the previously
developed \chi^2-technique (Hatziminaoglou et al 2002), that fits the overall
spectral energy distributions to template spectra and determines the best
fitting template.
The observed number counts, colour-magnitude diagrams, colour-colour diagrams
and colour distributions are presented and, to judge the quality of the data,
compared to simulations based on the predictions of a Galactic Model convolved
with the estimated completeness functions and the error model used to describe
the photometric errors of the data.
The resulting stellar catalogues and the objects identified as likely QSOs
and unresolved galaxies with coordinates, observed magnitudes with errors and
assigned spectral types by the -technique are presented and are
publicly available.Comment: Paper as it will appear in print. Complete figures and tables can be
obtained from: http://www.eso.org/science/eis/eis_pub/eis_pub.html. Astronomy
& Astrophysics, accepted for publicatio
Redshift-distance Survey of Early-type Galaxies: the ENEARc Cluster Sample
This paper presents data on the ENEARc subsample of the larger ENEAR survey
of the nearby early-type galaxies. The ENEARc galaxies belong to clusters and
were specifically chosen to be used for the construction of a D_n-sigma
template. The ENEARc sample includes new measurements of spectroscopic and
photometric parameters (redshift, velocity dispersion, line index Mg_2, and the
angular diameter d_n) as well as data from the literature. New spectroscopic
data are given for 229 cluster early-type galaxies and new photometry is
presented for 348 objects. Repeat and overlap observations with external data
sets are used to construct a final merged catalog consisting of 640 early-type
galaxies in 28 clusters. Objective criteria, based on catalogs of groups of
galaxies derived from complete redshift surveys of the nearby universe, are
used to assign galaxies to clusters. In a companion paper these data are used
to construct the template D_n-sigma distance relation for early-type galaxies
which has been used to estimate galaxy distances and derive peculiar velocities
for the ENEAR all-sky sample.Comment: 41 pages, 7 figures, and 8 tables. Accepted for publication in A
The Southern Sky Redshift Survey
We report redshifts, magnitudes and morphological classifications for 5369
galaxies with and 57 galaxies fainter than this limit, in two
regions covering a total of 1.70 steradians in the southern celestial
hemisphere. The galaxy catalog is drawn primarily from the list of non-stellar
objects identified in the Guide Star Catalog (Lasker et al. 1990, AJ 99, 2019;
hereafter GSC). The galaxies have positions accurate to about 1 arc sec and
magnitudes with an rms scatter of about 0.3 mag. We compute magnitudes
() from the relation between instrumental GSC magnitudes and the
photometry by Lauberts & Valentijn (1989). From a comparison with CCD
photometry, we find that our system is homogeneous across the sky and
corresponds to magnitudes measured at the isophotal level 26 mag
arcsec. The precision of the radial velocities is of \sim 40 km/s and
the redshift survey is more than 99% complete to the = 15.5
magnitude limit. This sample is in the direction opposite to the CfA2; in
combination the two surveys provide an important database for studies of the
properties of galaxies and their large-scale distribution in the nearby
Universe.Comment: 20 pages, uses AASTeX 4.0 macros. Includes 3 tables and 4 Postscripts
figures. Scheduled for publication in the AJ 1998 July issu
ESO Imaging Survey. Deep Public Survey: Multi-Color Optical Data for the Chandra Deep Field South
This paper presents multi-passband optical data obtained from observations of
the Chandra Deep Field South (CDF-S), located at alpha ~ 3h 32m, delta ~ -27d
48m. The observations were conducted at the ESO/MPG 2.2m telescope at La Silla
using the 8kx8k Wide-Field Imager (WFI). This data set, taken over a period of
one year, represents the first field to be completed by the ongoing Deep Public
Survey (DPS) being carried out by the ESO Imaging Survey (EIS) project. This
paper describes the optical observations, the techniques employed for
un-supervised pipeline processing and the general characteristics of the final
data set. The paper includes data taken in six different filters U'UBVRI. The
data cover an area of about 0.25 square degrees reaching 5 sigma limiting
magnitudes of U'_AB=26.0, U_AB=25.7, B_AB=26.4$, V_AB=25.4, R_AB=25.5 and I_AB=
24.7 mag, as measured within a 2xFWHM aperture. The optical data covers the
area of ~ 0.1Comment: 13 pages, 19 postscript figures, Figure 3,4,7,10 are available in
jpeg format, use aa.cls style. The full postscript of the paper is available
at http://www.eso.org/science/eis/eis_pub/eis_pub.htm