Abstract. We present calibrations of the effective temperatures of giant stars versus [Fe/H] and colours (U. These calibrations are based on a large sample of field and globular cluster stars which roughly cover spectral types from F0 to K5. Their effective temperatures, scaled to direct T eff determinations via reliable angular diameter measurements, were derived by applying the infrared flux method. The empirical relations have been fitted to polynomials of the form θ eff = P (colour, [Fe/H]) by using the least squares method. The precision of the fits ranges from 40 K for (V −K) to 170 K for (J −H). We tabulate intrinsic colours of giant stars in the ranges: 3500 K ≤ T eff ≤ 8000 K; −3.0 ≤ [Fe/H] ≤ +0.5. We also present the calibration of BC(V) as a function of log(T eff ) and metallicity. Finally, we compare the resulting scale of temperatures with previous works.

We study the kinematic properties of the ionised gas outflows and ambient interstellar medium (ISM) in a large and representative sample of local luminous and ultra-luminous infrared galaxies (U/LIRGs) (58 systems, 75 galaxies) at galactic and sub-galactic (i.e., star-forming clumps) scales, thanks to integral field spectroscopy (IFS)-based high signal-to-noise integrated spectra. The velocity dispersion of the ionized ISM in U/LIRGs ( σ ∼ 70 km s −1 ) is larger than in lower luminosity local star-forming galaxies ( σ ∼ 25 km s −1 ). While for isolated disc LIRGs star formation appears to sustain turbulence, gravitational energy release associated with interactions and mergers plays an important role in driving σ in the U/LIRG range. We find that σ has a dependency on the star formation rate density (Σ SFR ), which is weaker than expected if it were driven by the energy released by the starburst. The relatively small role of star formation (SF) driving the σ in U/LIRGs is reinforced by the lack of an increase in σ associated with high luminosity SF clumps. We also find that the impact of an active galactic nucleus (AGN) in ULIRGs is strong, increasing on average σ by a factor 1.5. Low-z U/LIRGs cover a range of velocity dispersion (σ ∼ 30 to 100 km s −1 ) and star formation rate density (Σ SFR ∼ 0.1 to 20 M yr −1 kpc −2 ) similar to those of high-z SFGs. Moreover, the observed weak dependency of σ on Σ SFR for local U/LIRGs (σ ∝ Σ +0.06 SFR ) is in very good agreement with that measured in some high-z samples. The presence of ionized gas outflows in U/LIRGs seems universal based on the detection of a broad, usually blueshifted, Hα line. The observed dependency of the maximum velocity of the outflow (V max ) on the star formation rate (SFR) is of the type+0.24 . We find that AGNs in U/LIRGs are able to generate faster (∼×2) and more massive (∼× 1.4) ionized gas outflows than pure starbursts. The derived ionized mass loading factors (η) are in general below 1, with only a few AGNs above this limit. The escaping gas fraction is low with only less massive (log(M dyn /M ) < 10.4) U/LIRGs having outflowing terminal velocities higher than their escape velocities, and more massive galaxies retaining the gas, even if they host an AGN. The observed average outflow properties in U/LIRGs are similar to high-z galaxies of comparable SFR. However, while high-z galaxies seem to require Σ SFR > 1 M yrfor launching strong outflows, this threshold is not observed in low-z U/LIRGs even after correcting for the differential fraction of the gas content. In the bright SF clumps found in LIRGs, ionized gas outflows appear to be very common (detection rate over 80%). Their observed properties are less extreme than those associated with the entire galaxy. The clumps in LIRGs follow the general size-L-σ scaling relations found for low-and high-z clumps, though they are in general smaller, less luminous, and are characterized by lower σ than at high-z. For a given observed (no internal extinction correction applied) star formation...

We present a simple set of kinematic criteria that can distinguish between galaxies dominated by ordered rotational motion and those involved in major merger events. Our criteria are based on the dynamics of the warm ionized gas (as traced by H) within galaxies, making this analysis accessible to high-redshift systems, whose kinematics are primarily traceable through emission features. Using the method of kinemetry (developed by Krajnović and coworkers), we quantify asymmetries in both the velocity and velocity dispersion maps of the warm gas, and the resulting criteria enable us to empirically differentiate between nonmerging and merging systems at high redshift. We apply these criteria to 11 of our best-studied rest-frame UV/optical-selected z $ 2 galaxies for which we have near-infrared integralfield spectroscopic data from SINFONI on the VLT. Of these 11 systems, we find that >50% have kinematics consistent with a single rotating disk interpretation, while the remaining systems are more likely undergoing major mergers. This result, combined with the short formation timescales of these systems, provides evidence that rapid, smooth accretion of gas plays a significant role in galaxy formation at high redshift.

Abstract. -We have applied the InfraRed Flux Method (IRFM) to a sample of 475 dwarfs and subdwarfs in order to derive their effective temperatures with a mean accuracy of about 1.5%. We have used the new homogeneous grid of theoretical model atmosphere flux distributions developed by Kurucz (1991Kurucz ( , 1993 for the application of the IRFM. The atmospheric parameters of the stars cover, roughly, the ranges: 3500 K ≤ Teff ≤ 8000 K; −3.5 ≤ [Fe/H] ≤ +0.5; 3.5 ≤ log(g) ≤ 5. The monocromatic infrared fluxes at the continuum, and the bolometric fluxes are derived using recent results, which satisfy the accuracy requeriments of the work. Photometric calibrations have been revised and applied to estimate metallicities, although direct spectroscopic determinations were preferred when available. The adopted infrared absolute flux calibration, based on direct optical measurements of angular stellar diameters, sets the effective temperatures determined using the IRFM on the same scale than those obtained by direct methods. We derive three temperatures, TJ , TH and TK , for each star using the monochromatic fluxes at different infrared wavelengths in the photometric bands J , H, and K. They show good consistency over 4000 K, and no trend with wavelength may be appreciated. We provide a detailed description of the steps followed for the application of the IRFM, as well as the sources of the errors associated to the different inputs of the method, and their transmission into the final temperatures. We also provide comparison with previous works.

Context. The observational study of star-formation relations in galaxies is central for unraveling the related physical processes that are at work on local and global scales. It is still debated whether star formation can be described by a universal law that remains valid in different populations of galaxies. Aims. We aim to expand the sample of extreme starbursts, represented by local luminous and ultra-luminous infrared galaxies (LIRGs and ULIRGs), with high-quality observations in the 1-0 line of HCN, which is taken as a proxy for the dense molecular gas content. The new data presented in this work allow us to enlarge in particular the number of LIRGs studied in HCN by a factor 3 compared to previous works. The chosen LIRG sample has a range of HCN luminosities that partly overlaps with that of the normal galaxy population. We study if a universal law can account for the star-formation relations observed for the dense molecular gas in normal star-forming galaxies and extreme starbursts and explore the validity of different theoretical prescriptions of the star-formation law. Methods. We have used the IRAM 30 m telescope to observe a sample of 19 LIRGs in the 1-0 lines of CO, HCN and HCO + . The galaxies were extracted from a sample of local LIRGs with available high-quality and high-resolution images obtained at optical, near and mid IR wavelengths, which probe the star-formation activity. We therefore derived the star-formation rates using different tracers and determined the sizes of the star-forming regions of all targets. Results. The analysis of the new data proves that the efficiency of star formation in the dense molecular gas (SFE dense ) of extreme starbursts is a factor 3-4 higher compared to normal galaxies. Kennicutt-Schmidt (KS) power laws were also derived. We find a duality in KS laws that is further reinforced if we account for the likely different conversion factor for HCN (α HCN ) in extreme starbursts and for the unobscured star-formation rate in normal galaxies. This result extends the more extreme bimodal behavior of star-formation laws that was derived from CO molecular lines by two recent surveys to the higher molecular densities probed by HCN lines. Conclusions. We compared our observations with the predictions of theoretical models in which the efficiency of star formation is determined by the ratio of a constant star-formation rate per free-fall time (SFR ff ) to the local free-fall time (t ff ). We find that it is possible to fit the observed differences in the SFE dense between normal galaxies and LIRGs/ULIRGs using a common constant SFR ff and a set of physically acceptable HCN densities, but only if SFR ff ∼ 0.005-0.01 and/or if α HCN is a factor of ∼a few lower than our favored values. Star-formation recipes that explicitly depend on the galaxy global dynamical time scales do not significantly improve the fit to the new HCN data presented in this work.

We present and discuss the 2D kinematic properties of the ionized gas (Hα) in a sample of 38 local (ultra) luminous infrared galaxies [(U)LIRGs] (31 LIRGs and 7 ULIRGs, 51 individual galaxies) observed with VIMOS at the Very Large Telescope using optical integral field spectroscopy (IFS). This sample covers well the less studied LIRG luminosity range and includes the morphological types corresponding to the different phases along the merging process (i.e., isolated disks, interacting systems, and mergers). The majority of the galaxies have two main kinematically distinct components. One component (i.e., narrow or systemic) extends over the whole line-emitting region and is characterized by small to intermediate velocity dispersions (i.e., σ from 30 to 160 km s −1 ). The second component (broad) has in general a larger velocity dispersion (up to 320 km s −1 ); it is mainly found in the inner regions and is generally blueshifted with respect to the systemic component. The largest extensions and extreme kinematic properties of the broad component are observed in interacting and merging systems, and they are likely associated with nuclear outflows. The systemic component traces the overall velocity field showing a large variety of kinematic 2D structures, from very regular velocity patterns typical of pure rotating disks (29%) to kinematically perturbed disks (47%) and highly disrupted and complex velocity fields (24%). Thus, most of the objects (76%) are dominated by rotation. We find that rotation is more relevant in LIRGs than in ULIRGs. There is a clear correlation between the different phases of the merging process and the mean kinematic properties inferred from the velocity maps. In particular, isolated disks, interacting galaxies, and merging systems define a sequence of increasing mean velocity dispersion, and decreasing velocity field amplitude, characterized by average dynamical ratios (v * shear /σ mean ) of 4.7, 3.0 and 1.8, respectively. We also find that the ratio between the nuclear (σ c ) and the mean velocity dispersions (σ mean ) vs. σ mean is an excellent discriminating plane between disks and interacting/merging systems: disks show a mean ratio a factor of 2 larger than those characterizing the other two classes. The LIRGs classified as isolated disks have similar velocity amplitudes but larger mean velocity dispersions (44 vs. 24 km s −1 ) than local spirals, implying a larger turbulence and thicker disks. Interacting systems and mergers have values closer to those of low velocity dispersion ellipticals/lenticular galaxies (E/SOs). The subclass of (U)LIRGs classified as mergers have kinematic properties similar to those shown by the Lyman break analogs (LBAs), although the dynamical mass of LBAs is five times lower on average. Therefore, despite the difference in mass and dust content, the kinematics of these two local populations appears to have significant noncircular motions. These motions may be induced by the tidal forces, producing dynamically hot systems. The dynamical masses range from ∼ ...

Recent observations have revealed massive galactic molecular outflows 1-3 that may have physical conditions (high gas densities 4-6 ) required to form stars. Indeed, several recent models predict that such massive galactic outflows may ignite star formation within the outflow itself 7-11 . This star-formation mode, in which stars form with high radial velocities, could contribute to the morphological evolution of galaxies 12 , to the evolution in size and velocity dispersion of the spheroidal component of galaxies 11,13 , and would contribute to the population of highvelocity stars, which could even escape the galaxy 13 . Such star formation could provide in-situ chemical enrichment of the circumgalactic and intergalactic medium (through supernova explosions of young stars on large orbits), and some models also predict that it may contribute substantially to the global star formation rate observed in distant galaxies 9 . Although there exists observational evidence for star formation triggered by outflows or jets into their host galaxy, as a consequence of gas compression, evidence for star formation occurring within galactic outflows is still missing. Here we report new spectroscopic observations that unambiguously reveal star formation occurring in a galactic outflow at a redshift of 0.0448. The inferred star formation rate in the outflow is larger than 15 M ¤ /yr. Star formation may also be occurring in other galactic outflows, but may have been missed by previous observations owing to the lack of adequate diagnostics 14,15 .IRAS F23128-5919 is a merging system (Fig.1a), in which the southern nucleus hosts an obscured active nucleus (AGN), detected in the X-rays 16 . Past observations had already revealed a prominent outflow developing from the southern nucleus 14,15,[17][18][19] , driven by the nuclear starburst, or by the AGN, or both. We analyzed archival Very Large Telescope (VLT) spectroscopic observations, obtained with the MUSE instrument, of the optical nebular lines to better characterize the outflow. The nebular emission line profiles can be clearly separated into a narrow component, associated with the interstellar medium in the two galactic disks, and a very broad (Full Width Half Maximum, FWHM~600-1,000 km/s), predominantly blueshifted component tracing the outflow. The velocity field, velocity dispersion, surface brightness maps of the two components are shown in Fig. 1a. The narrow component (bottom row in Fig. 1a) is probably tracing the bulk of the dynamics of the two merging disks. The outflow traced by the broad blueshifted component (top row in Fig. 1a) of the nebular lines extends towards the East of the southern nucleus for about 7-9 kpc (8"-10"), beyond the optical galactic disk. A receding counter-outflow is also observed in the opposite direction, i.e. towards the West (although weaker, owing to extinction by the galactic disk).We have observed the central and eastern outflows with the X-shooter spectrograph at the VLT, which enabled the detection of spectral diagnostics over the en...

We present an original phenomenological model to describe the evolution of galaxy number counts, morphologies, and spectral energy distributions across a wide range of redshifts (0.2 < z < 15) and stellar masses [log(M/M ) ≥ 6]. Our model follows observed mass and luminosity functions of both star-forming and quiescent galaxies, and reproduces the redshift evolution of colors, sizes, star-formation and chemical properties of the observed galaxy population. Unlike other existing approaches, our model includes a self-consistent treatment of stellar and photoionized gas emission and dust attenuation based on the BEAGLE tool. The mock galaxy catalogs generated with our new model can be used to simulate and optimize extragalactic surveys with future facilities such as the James Webb Space Telescope (JWST), and to enable critical assessments of analysis procedures, interpretation tools, and measurement systematics for both photometric and spectroscopic data. As a first application of this work, we make predictions for the upcoming JWST Advanced Deep Extragalactic Survey (JADES), a joint program of the JWST/NIRCam and NIRSpec Guaranteed Time Observations teams. We show that JADES will detect, with NIRCam imaging, thousands of galaxies at z 6, and tens at z 10 at m AB 30 (5σ) within the 236 arcmin 2 of the survey. The JADES data will enable accurate constraints on the evolution of the UV luminosity function at z > 8, and resolve the current debate about the rate of evolution of galaxies at z 8. Ready to use mock catalogs and software to generate new realizations are publicly available as the JAdes extraGalactic Ultradeep Artificial Realizations (JAGUAR) package.