13 research outputs found
CALIFA : a diameter-selected sample for an integral field spectroscopy galaxy survey
JMA acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild).We describe and discuss the selection procedure and statistical properties of the galaxy sample used by the Calar Alto Legacy Integral Field Area (CALIFA) survey, a public legacy survey of 600 galaxies using integral field spectroscopy. The CALIFA "mother sample" was selected from the Sloan Digital Sky Survey (SDSS) DR7 photometric catalogue to include all galaxies with an r-band isophotal major axis between 45 '' and 79 : 2 '' and with a redshift 0 : 005 M-r > -23 : 1 and over a stellar mass range between 10(9.7) and 10(11.4) M-circle dot. In particular, within these ranges, the diameter selection does not lead to any significant bias against - or in favour of - intrinsically large or small galaxies. Only below luminosities of M-r = -19 (or stellar masses <10(9.7) M-circle dot) is there a prevalence of galaxies with larger isophotal sizes, especially of nearly edge-on late-type galaxies, but such galaxies form <10% of the full sample. We estimate volume-corrected distribution functions in luminosities and sizes and show that these are statistically fully compatible with estimates from the full SDSS when accounting for large-scale structure. For full characterization of the sample, we also present a number of value-added quantities determined for the galaxies in the CALIFA sample. These include consistent multi-band photometry based on growth curve analyses; stellar masses; distances and quantities derived from these; morphological classifications; and an overview of available multi-wavelength photometric measurements. We also explore different ways of characterizing the environments of CALIFA galaxies, finding that the sample covers environmental conditions from the field to genuine clusters. We finally consider the expected incidence of active galactic nuclei among CALIFA galaxies given the existing pre-CALIFA data, finding that the final observed CALIFA sample will contain approximately 30 Sey2 galaxies.Peer reviewe
Two-dimensional multi-component photometric decomposition of CALIFA galaxies
We present a two-dimensional multi-component photometric decomposition of 404 galaxies from the Calar Alto Legacy Integral Field Area Data Release 3 (CALIFA-DR3). They represent all possible galaxies with no clear signs of interaction and not strongly inclined in the final CALIFA data release. Galaxies are modelled in the g, r, and i Sloan Digital Sky Survey (SDSS) images including, when appropriate, a nuclear point source, bulge, bar, and an exponential or broken disc component. We use a human-supervised approach to determine the optimal number of structures to be included in the fit. The dataset, including the photometric parameters of the CALIFA sample, is released together with statistical errors and a visual analysis of the quality of each fit. The analysis of the photometric components reveals a clear segregation of the structural composition of galaxies with stellar mass. At high masses (log(M⋆/M⊙) > 11), the galaxy population is dominated by galaxies modelled with a single Sérsic or a bulge+disc with a bulge-to-total (B/T) luminosity ratio B/T > 0.2. At intermediate masses (9.5 < log(M⋆/M⊙) < 11), galaxies described with bulge+disc but B/T < 0.2 are preponderant, whereas, at the low mass end (log(M⋆/M⊙)< 9.5), the prevailing population is constituted by galaxies modelled with either pure discs or nuclear point sources+discs (i.e., no discernible bulge). We obtain that 57% of the volume corrected sample of disc galaxies in the CALIFA sample host a bar. This bar fraction shows a significant drop with increasing galaxy mass in the range 9.5 < log(M⋆/M⊙) < 11.5. The analyses of the extended multi-component radial profile result in a volume-corrected distribution of 62%, 28%, and 10% for the so-called Type I (pure exponential), Type II (down-bending), and Type III (up-bending) disc profiles, respectively. These fractions are in discordance with previous findings. We argue that the different methodologies used to detect the breaks are the main cause for these differences.PostprintPeer reviewe
Morpho-kinematic properties of field S0 bulges in the CALIFA survey
We study a sample of 28 S0 galaxies extracted from the integral-field
spectroscopic (IFS) survey CALIFA. We combine an accurate two-dimensional (2D)
multi-component photometric decomposition with the IFS kinematic properties of
their bulges to understand their formation scenario. Our final sample is
representative of S0s with high stellar masses ().
They lay mainly on the red sequence and live in relatively isolated
environments similar to that of the field and loose groups. We use our 2D
photometric decomposition to define the size and photometric properties of the
bulges, as well as their location within the galaxies. We perform mock
spectroscopic simulations mimicking our observed galaxies to quantify the
impact of the underlying disc on our bulge kinematic measurements (
and ). We compare our bulge corrected kinematic measurements with the
results from Schwarzschild dynamical modelling. The good agreement confirms the
robustness of our results and allows us to use bulge reprojected values of
and . We find that the photometric ( and ) and
kinematic ( and ) properties of our field S0 bulges are not
correlated. We demonstrate that this morpho-kinematic decoupling is intrinsic
to the bulges and it is not due to projection effects. We conclude that
photometric diagnostics to separate different types of bulges (disc-like vs
classical) might not be useful for S0 galaxies. The morpho-kinematics
properties of S0 bulges derived in this paper suggest that they are mainly
formed by dissipation processes happening at high redshift, but dedicated
high-resolution simulations are necessary to better identify their origin.Comment: 31 pages, 19 figures. Accepted for publication in MNRA
Speech Illusions in People at Clinical High Risk for Psychosis Linked to Clinical Outcome
BACKGROUND AND HYPOTHESIS: Around 20% of people at clinical high risk (CHR) for psychosis later develop a psychotic disorder, but it is difficult to predict who this will be. We assessed the incidence of hearing speech (termed speech illusions [SIs]) in noise in CHR participants and examined whether this was associated with adverse clinical outcomes.
STUDY DESIGN: At baseline, 344 CHR participants and 67 healthy controls were presented with a computerized white noise task and asked whether they heard speech, and whether speech was neutral, affective, or whether they were uncertain about its valence. After 2 years, we assessed whether participants transitioned to psychosis, or remitted from the CHR state, and their functioning.
STUDY RESULTS: CHR participants had a lower sensitivity to the task. Logistic regression revealed that a bias towards hearing targets in stimuli was associated with remission status (OR = 0.21, P = 042). Conversely, hearing SIs with uncertain valence at baseline was associated with reduced likelihood of remission (OR = 7.72. P = .007). When we assessed only participants who did not take antipsychotic medication at baseline, the association between hearing SIs with uncertain valence at baseline and remission likelihood remained (OR = 7.61, P = .043) and this variable was additionally associated with a greater likelihood of transition to psychosis (OR = 5.34, P = .029).
CONCLUSIONS: In CHR individuals, a tendency to hear speech in noise, and uncertainty about the affective valence of this speech, is associated with adverse outcomes. This task could be used in a battery of cognitive markers to stratify CHR participants according to subsequent outcomes
VizieR Online Data Catalog: CALIFA color/metallicity gradients connections (Marino+, 2016)
We have selected the 350 galaxies observed by the CALIFA survey (Sanchez et al., 2012A&A...538A...8S) at the CAHA 3.5m telescope with Potsdam Multi Aperture Spectrograph (PMAS) in the PPak mode and processed by the CALIFA v1.5 pipeline up to September 2014. The SDSS g' and r' SB and (g'-r') color profiles were derived using the DR10 data products, in particular, we used the swarp mosaicking code (Ahn et al., 2014ApJS..211...17A). We obtain spectroscopic information for ~15130 HII regions (or complexes) from our 324 CALIFA data cubes using HII explorer
VizieR Online Data Catalog: 2D decomposition of CALIFA galaxies (Mendez-Abreu+, 2017)
Table 1 reports the results from the multi-component photometric decomposition in the g-, r-, and i-bands. (1 data file)
VizieR Online Data Catalog: 2D decomposition of CALIFA galaxies (Mendez-Abreu+, 2017)
Table 1 reports the results from the multi-component photometric decomposition in the g-, r-, and i-bands. (1 data file)
CALIFA:a diameter-selected sample for an integral field spectroscopy galaxy survey
We describe and discuss the selection procedure and statistical properties of the galaxy sample used by the Calar Alto Legacy Integral Field Area (CALIFA) survey, a public legacy survey of 600 galaxies using integral field spectroscopy. The CALIFA "mother sample" was selected from the Sloan Digital Sky Survey (SDSS) DR7 photometric catalogue to include all galaxies with an r-band isophotal major axis between 45 '' and 79 : 2 '' and with a redshift 0 : 005 <z <0 : 03. The mother sample contains 939 objects, 600 of which will be observed in the course of the CALIFA survey. The selection of targets for observations is based solely on visibility and thus keeps the statistical properties of the mother sample. By comparison with a large set of SDSS galaxies, we find that the CALIFA sample is representative of galaxies over a luminosity range of -19 > M-r > -23 : 1 and over a stellar mass range between 10(9.7) and 10(11.4) M-circle dot. In particular, within these ranges, the diameter selection does not lead to any significant bias against - or in favour of - intrinsically large or small galaxies. Only below luminosities of M-r = -19 (or stellar masses <10(9.7) M-circle dot) is there a prevalence of galaxies with larger isophotal sizes, especially of nearly edge-on late-type galaxies, but such galaxies form <10% of the full sample. We estimate volume-corrected distribution functions in luminosities and sizes and show that these are statistically fully compatible with estimates from the full SDSS when accounting for large-scale structure. For full characterization of the sample, we also present a number of value-added quantities determined for the galaxies in the CALIFA sample. These include consistent multi-band photometry based on growth curve analyses; stellar masses; distances and quantities derived from these; morphological classifications; and an overview of available multi-wavelength photometric measurements. We also explore different ways of characterizing the environments of CALIFA galaxies, finding that the sample covers environmental conditions from the field to genuine clusters. We finally consider the expected incidence of active galactic nuclei among CALIFA galaxies given the existing pre-CALIFA data, finding that the final observed CALIFA sample will contain approximately 30 Sey2 galaxies.</p