Aims. We present new 2D high resolution Fabry–Perot spectroscopic observations of 152 star-forming galaxies that are part of the Herschel Reference Survey (HRS), which is a complete K-band selected, ...volume-limited sample of nearby galaxies that spans a wide range of stellar mass and morphological types. Methods. By using improved data reduction techniques, that provide adaptive binning based on Voronoi tessellation, and using large field-of-view observations, we derived high spectral resolution (R > 10 000) Hα datacubes from which we computed Hα maps and radial 2D velocity fields that are based on several of thousand independent measurements. A robust method based on such fields allowed us to accurately compute rotation curves and kinematical parameters, for which uncertainties are calculated using a method based on the power spectrum of the residual velocity fields. Results. We checked the consistency of the rotation curves by comparing our maximum rotational velocities to those derived from H I data, and by computing the i-band, NIR, stellar, and baryonic Tully-Fisher relations. We used this set of kinematical data combined with those available at other frequencies to study, for the first time, the relation between the dynamical and the total baryonic mass (stars, atomic and molecular gas, metals, and dust) and to derive the baryonic and dynamical main sequence on a representative sample of the local universe.
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IMAGES Puech, M.; Flores, H.; Hammer, F. ...
Astronomy and astrophysics (Berlin),
06/2008, Volume:
484, Issue:
1
Journal Article
Peer reviewed
Open access
Using the multi-integral field spectrograph GIRAFFE at VLT, we have derived the K-band Tully-Fisher relation (TFR) at z sim 0.6 for a representative sample of 65 galaxies with emission lines ...(W_\mathrm{0}\mathrm\ge15 similar to \AA). We confirm that the scatter in the z sim 0.6 TFR is caused by galaxies with anomalous kinematics, and find a positive and strong correlation between the complexity of the kinematics and the scatter that they contribute to the TFR. Considering only relaxed-rotating disks, the scatter, and possibly also the slope, of the TFR, do not appear to evolve with redshift. We detect an evolution of the K-band TFR zero point between z sim 0.6 and z =0, which, if interpreted as an evolution of the K-band luminosity of rotating disks, would imply that a brightening of 0.66 pm 0.14 mag occurs between z sim 0.6 and z =0. Any disagreement with the results of Flores et al. (2006, A&A, 455, 107) are attributed to both an improvement of the local TFR and the more detailed accurate measurement of the rotation velocities in the distant sample. Most of the uncertainty can be explained by the relatively coarse spatial-resolution of the kinematical data. Because most rotating disks at z sim 0.6 are unlikely to experience further merging events, one may assume that their rotational velocity, which is taken as a proxy of the total mass, does not evolve dramatically. If true, our result implies that rotating disks observed at z sim 0.6 are rapidly transforming their gas into stars, to be able to double their stellar masses and be observed on the TFR at z =0. The rotating disks observed are indeed emission-line galaxies that are either starbursts or LIRGs, which implies that they are forming stars at a high rate. Thus, a significant fraction of the rotating disks are forming the bulk of their stars within 6 to 8 Gyr, in good agreement with former studies of the evolution of the mass-metallicity relationship.
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We report the results of a kinematical Hα survey of the Large Magellanic Cloud (LMC) presented in the form of a kinematical and photometric catalogue of 210 H ii regions. The observations have been ...obtained with a scanning Fabry–Perot interferometer that produced data cubes corresponding to 66 different pointings over this galaxy, each with a field of view of 38 arcmin, covering almost the whole extent of the LMC. We find a bimodal distribution of the Hα luminosity of LMC H ii regions. We also derive the local star formation and star formation rate (SFR) per unit area of the nebulae, concluding that star formation in the LMC has proceeded until the present time at an average rate of roughly 0.11 M⊙ yr−1. Also, we do not find any correlation between the SFR or ΣSFR with ΔV (full width at half-maximum for a single Gaussian profile and the difference in velocities for multiple-components velocity profiles), the diameter, the distance to the kinematical centre of the LMC and age of the nebulae. Over most of the LMC ΔV appears to be of the order of 30 km s−1. However, in a few regions the ΔV of the velocity profiles is as large as 50–100 kms−1, corresponding to identified supernova remnants and superbubbles undergoing expansion motions.
We present new Fabry-Perot observations for a sample of 42 galaxies located in 12 compact groups of galaxies: HCG 1, HCG 14, HCG 25, HCG 44, HCG 53, HCG 57, HCG 61, HCG 69, HCG 93, VV 304, LGG 455 ...and Arp 314. From the 42 observed galaxies, a total of 26 objects are spiral galaxies, which range from Sa to Im morphological types. The remaining 16 objects are E, S0 and S0a galaxies. Using these observations, we have derived velocity maps, monochromatic and velocity dispersion maps for 24 galaxies, where 18 are spiral, three are S0a, two are S0 and one is an Im galaxy. From the 24 velocity fields obtained, we could derive rotation curves for 15 galaxies; only two of them exhibit rotation curves without any clear signature of interactions. Based on kinematic information, we have evaluated the evolutionary stage of the different groups of the current sample. We identify groups that range from having no Hα emission to displaying an extremely complex kinematics, where their members display strongly perturbed velocity fields and rotation curves. In the case of galaxies with no Hα emission, we suggest that past galaxy interactions removed their gaseous components, thereby quenching their star formation. However, we cannot discard that the lack of Hα emission is linked with the detection limit for some of our observations.
This is the first part of an Hα kinematics follow-up survey of the Spitzer Infrared Nearby Galaxies Survey (SINGS) sample. The data for 28 galaxies are presented. The observations were done on three ...different telescopes with Fabry—Perot of New Technology for the Observatoire du mont Megantic (FaNTOmM), an integral field photon-counting spectrometer, installed in the respective focal reducer of each telescope. The data reduction was done through a newly built pipeline with the aim of producing the most homogenous data set possible. Adaptive spatial binning was applied to the data cubes in order to get a constant signal-to-noise ratio across the field of view. Radial velocity and monochromatic maps were generated using a new algorithm, and the kinematical parameters were derived using tilted-ring models.
Using a specialized technique sensitive to the presence of expanding ionized gas, we have detected a set of three concentric expanding shells in an H ii region in the nearby spiral galaxy M33. After ...mapping the kinematics in Hα with Fabry–Perot spectroscopy, we used slit spectra to measure the intensities of the S ii doublet at λλ671.9, 673.1 nm and the N ii doublet at λλ645.8, 658.3 nm to corroborate the kinematics and apply diagnostic tests using line ratios. These showed that the expanding shells are shock dominated as would be the case if they had originated with supernova explosions. Estimating their kinetic energies, we find fairly low values, indicating a fairly advanced stage of evolution. We obtain density, mass and parent star mass estimates, which, along with the kinetic energies, are inconsistent with the simplest models of shock–interstellar medium interaction. We propose that the presence and properties of an inhomogeneous medium offer a scenario which can account for these observations, and discuss the implications. Comparing our results with data from the literature supports the combined presence of an H ii region and supernova remnant material at the observed position.
We present GALEX UV observations of a sample of low surface brightness (LSB) galaxies for which H i data are available, allowing us to estimate their star formation efficiency. We find that the UV ...light extends to larger radii than the optical light (some galaxies, but not all, look similar to the recently discovered XUV-disk galaxies). Using a standard calibration to convert the UV light into star formation rates, we obtain lower star formation efficiencies in LSB galaxies than in high surface brightness galaxies by about one order of magnitude. We show, however, that standard calibrations may not apply to these galaxies, as the FUV-NUV color obtained from the two GALEX bands (FUV and NUV; image and 2267 Aa, respectively) is redder than expected for star-forming galaxies. This color can be interpreted as a result of internal extinction, modified initial mass function, or star formation histories characterized by bursts followed by quiescent phases. Our analysis favors this latter hypothesis.
We used K-band photometry, maximum rotational velocities derived from Fabry-Perot data and H i observed and predicted masses to study, for the first time, the K band, stellar and baryonic ...Tully-Fisher relations for galaxies in Hickson compact groups. We compared these relations with the ones defined for galaxies in less dense environments from the Gassendi HAlpha survey of Spirals and from a sample of gas-rich galaxies. We find that most of the Hickson compact group galaxies lie on the K-band Tully-Fisher relation defined by field galaxies with a few low-mass outliers, namely HCG 49b and HCG 96c, which appear to have had strong recent burst of star formation. The stellar Tully-Fisher relation for compact group galaxies presents a similar dispersion to that of the K-band relation, and it has no significant outliers when a proper computation of the stellar mass is done for the strongly star-forming galaxies. The scatter in these relations can be reduced if the gaseous component is taken into account, i.e. if a baryonic Tully-Fisher relation is considered. In order to explain the positions of the galaxies off the K-band Tully-Fisher relation, we favour a scenario in which their luminosities are brightened due to strong star formation or AGN activity. We argue that strong bursts of star formation can affect the B- and K-band luminosities of HCG 49b and HCG 96c and in the case of the latter also AGN activity may affect the K-band magnitude considerably, without affecting their total masses.
We present a study of the kinematics and the physical properties of the central region of the Hickson Compact Group 31 (HCG 31), focusing on the HCG 31A+C system, using integral field spectroscopy ...data taken with the Gemini South Telescope. The main players in the merging event (galaxies A and C) are two dwarf galaxies, which have had one close encounter, given the observed tidal tails, and may now be in their second approach, and are possibly about to merge. We present new velocity fields and Hα emission, stellar continuum, velocity dispersion, electron density, Hα equivalent-width and age maps. Considering the high spatial resolution of the integral field unit data, we were able to measure various components and estimate their physical parameters, spatially resolving the different structures in this region. Our main findings are the following: (1) We report for the first time the presence of a super stellar cluster next to the burst associated with the HCG 31C central blob, related to the high values of velocity dispersion observed in this region as well as to the highest value of stellar continuum emission. This may suggest that this system is cleaning its environment through strong stellar winds that may then trigger a strong star formation event in its neighbourhood. (2) Among other physical parameters, we estimate L(Hα) ∼ 14 × 1041 erg s−1 and the star formation rate, SFR ∼11 M⊙ yr−1 for the central merging region of HCG 31A+C. These values indicate a high star formation density, suggesting that the system is part of a merging object, supporting previous scenarios proposed for this system.
This is the second part of an Hα kinematics follow-up survey of the Spitzer Infrared Nearby Galaxies Survey (SINGS) sample. The aim of this paper is to shed new light on the role of baryons and their ...kinematics and on the dark/luminous matter relation in the star-forming regions of galaxies, in relation with studies at other wavelengths. The data for 37 galaxies are presented. The observations were made using Fabry–Perot interferometry with the photon-counting camera FaNTOmM on four different telescopes, namely the Canada–France–Hawaii 3.6-m, the ESO La Silla 3.6-m, the William Herschel 4.2-m and the Observatoire du mont Mégantic 1.6-m telescopes. The velocity fields are computed using custom idl routines designed for an optimal use of the data. The kinematical parameters and rotation curves are derived using the gipsy software. It is shown that non-circular motions associated with galactic bars affect the kinematical parameters fitting and the velocity gradient of the rotation curves. This leads to incorrect determinations of the baryonic and dark matter distributions in the mass models derived from those rotation curves.
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