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We present observations of the type-2 Seyfert NGC 7172 obtained with the medium-resolution spectrometer (MRS) of the Mid-Infrared Instrument (MIRI) on board the James Webb Space Telescope (JWST). This galaxy hosts one of the lowest ionised gas mass outflow rates (Ṁout ∼ 0.005 M⊙ yr−1) in a sample of six active galactic nuclei (AGN) with similar bolometric luminosities (log Lbol ∼ 44 erg s−1) within the Galactic Activity, Torus, and Outflow Survey (GATOS). We aim to understand the properties of the ionised gas outflow and its impact on the host galaxy. We mainly used the ionised gas emission lines from the neon transitions, which cover a broad range of ionisation potentials (IPs) from ∼20 eV to ∼130 eV. We applied parametric and non-parametric methods to characterise the line emission and kinematics. The low excitation lines (IP < 25 eV, e.g. [Ne II]) trace the rotating disc emission. The high excitation lines (IP > 90 eV, e.g. [Ne V]), which are likely photoionised exclusively by the AGN, are expanding in the direction nearly perpendicular to the disc of the galaxy, with maximum projected velocities in the range of ∼350–500 km s−1. In particular, [Ne V] and [Ne VI] lines reveal a biconical ionised gas outflow emerging north-south from the nuclear region, extending at least ∼2.5″ N and 3.8″ S (projected distance of ∼450 and 680 pc, respectively). Most of the emission arising in the northern part of the cone was not previously detected due to obscuration. Given the almost face-on orientation of the outflow and the almost edge-on orientation of the galaxy, NGC 7172 may be a case of weak coupling. Nevertheless, we found evidence of positive feedback in two distinct outflowing clumps at projected distances of 3.1″ and 4.3″ (i.e. ∼560 and 780 pc) south-west of the AGN. We estimated a star formation rate in these regions using the [Ne II] and [Ne III] luminosities of 0.08 M⊙ yr−1, which is ∼10% of that found in the circumnuclear ring. The star formation activity might have been triggered by the interaction between the ionised gas outflow and the interstellar medium of the galaxy. [ABSTRACT FROM AUTHOR]

Context. The spatial coherence wavefront outer scale (ℒ0) characterizes the size of the largest turbulence eddies in Earth's atmosphere, determining low spatial frequency perturbations in the wavefront of the light captured by ground-based telescopes. Advances in adaptive optics (AO) techniques designed to compensate for atmospheric turbulence emphasize the crucial role of this parameter for the next generation of large telescopes. Aims. The motivation of this work is to introduce a novel technique for estimating ℒ0 from seeing-limited integral field spectroscopic (IFS) data. This approach is based on the impact of a finite ℒ0 on the light collected by the pupil entrance of a ground-based telescope. Methods. We take advantage of the homogeneity of IFS observations to generate band filter images spanning a wide wavelength range, enabling the assessment of image quality (IQ) at the telescope's focal plane. Comparing the measured wavelength-dependent IQ variation with predictions derived from a first-order analytical approach based on turbulence statistics simplifications using the von Kármán model provides valuable insights into the prevailing ℒ0 parameter during the observations. We applied the proposed technique to observations from the Multi-Unit Spectroscopic Explorer (MUSE) in the wide-field mode obtained at the Paranal Observatory. Results. Our analysis successfully validates the first-order analytical expression, which combines the seeing (ε0) and the ℒ0 parameters, to predict the IQ variations with the wavelength in ground-based astronomical data. However, we observed some discrepancies between the measured and predictions of the IQ that are analyzed in terms of uncertainties in the estimated ε0 and dome-induced turbulence contributions. Conclusions. This work constitutes the empirical validation of the analytical expression for estimating IQ at the focal plane of ground-based telescopes under specific ε0 and finite ℒ0 conditions. Additionally, we provide a simple methodology to characterize the ℒ0 and dome-seeing (εdome) as by-products of IFS observations routinely conducted at major ground-based astronomical observatories. [ABSTRACT FROM AUTHOR]

We explore the effect of AGN activity on the star formation history of galaxies by analysing the stellar population properties of 10 pairs of nearby twin galaxies – selected as being visually similar except for the presence of an AGN. The selection of such twin samples represents a method to study AGN feedback, as recently proposed by del Moral Castro et al. We use integral field unit (IFU) data from CALIFA, stacked within three fixed apertures. AGN galaxies in a twin pair suggest more evolved stellar populations than their non-AGN counterpart 90 per cent of the time, regardless of aperture size. A comparison with a large sample from SDSS confirms that most twins are representative of the general population, but in each twin the differences between twin members is significant. A set of targeted line strengths reveal the AGN member of a twin pair is older and more metal-rich than the non-AGN galaxy, suggesting AGN galaxies in our sample may either have an earlier formation time or follow a different star formation and chemical enrichment history. These results are discussed within two simple, contrasting hypotheses for the role played by AGN in galaxy evolution, which can be tested in the future at a greater detail with the use of larger data sets. [ABSTRACT FROM AUTHOR]

Introduction: Knowledge about residual deficiencies and their consequences on daily life activities among stroke patients living at home 1-year after the initial event managed in stroke units is poor. This multi-dimensional study assessed the types of deficiencies, their frequency and the consequences that the specific stroke had upon the daily life of patients. Methods: A cross-sectional survey, assessing, using standardized scales, 1 year post-stroke disabilities, limitations of activities, participation and quality of life, was carried out by telephone interview and by mail in a sample of stroke patients who returned home after having been initially managed in a stroke unit. Results: A total of 161 patients were included (142 able to answer the interview on their own; 19 needing a care-giver). Amongst a sub-group of the patients interviewed, 55.4% (95% Confidence Interval [47.1–63.7]) complained about pain and 60.0% (95% CI [51.4–68.6]) complained of fatigue; about 25% presented neuropsychological or neuropsychiatric disability. Whilst 87.3% (95% CI [81.7–92.9]) were independent for daily life activities, participation in every domains and quality of life scores, mainly in daily activity, pain, and anxiety subscales, were low. Conclusion: Despite a good 1-year post-stroke functional outcome, non-motor disabling symptoms are frequent amongst patients returned home and able to be interviewed, contributing to a low level of participation and a poor quality of life. Rehabilitation strategies focused on participation should be developed to break the vicious circle of social isolation and improve quality of life. [ABSTRACT FROM AUTHOR]

We present a pilot study aimed to identify large-scale galaxy properties that could play a role in activating a quiescent nucleus. To do so, we compare the properties of two isolated nearby active galaxies and their non-active twins selected from the Calar Alto Legacy Integral Field Area (CALIFA) survey. This pilot sample includes two barred and two unbarred galaxies. We characterize the stellar and ionized gas kinematics and also their stellar content. We obtain simple kinematic models by fitting the full stellar and ionized gas velocity fields and just the approaching or receding sides. We find that the analysed active galaxies present lopsided discs and higher values of the global stellar angular momentum (λ R ) than their non-active twins. This could be indicating that the stellar discs of the AGN gained angular momentum from the inflowing gas that triggered the nuclear activity. The inflow of gas could have been produced by a twisted disc instability in the case of the unbarred AGN, and by the bar in the case of the barred AGN. In addition, we find that the central regions of the studied active galaxies show older stellar populations than their non-active twins. The next step is to statistically explore these galaxy properties in a larger sample of twin galaxies. [ABSTRACT FROM AUTHOR]

We present a new method for the detection and characterization of expansion in galaxy discs based on Hα Fabry-Perot spectroscopy, taking advantage of the high spatial and velocity resolution of our instrument (GHαFaS). The method analyses multipeaked emission line profiles to find expansion along the line of sight on a point-by-point basis. At this stage we have centred our attention on the large-scale structures of expanding gas associated with H ii regions which show a characteristic pattern of expansion velocities, of the order of 100 km s−1, as a result of both bubble shape and projection effects. We show an example of the expansion map obtained with our method from a superbubble detected in the Antennae galaxies. We use the information obtained from the method to measure the relevant physical parameters of the superbubbles, including their ages which can be used to date young star clusters. [ABSTRACT FROM AUTHOR]

Context. Ionized gas kinematics provide important clues to the dynamical structure of galaxies and hold constraints to the processes driving their evolution. Aims. The motivation of this work is to provide an overall characterization of the kinematic behavior of the ionized gas of the galaxies included in the Calar Alto Legacy Integral field Area (CALIFA), offering kinematic clues to potential users of the CALIFA survey for including kinematical criteria in their selection of targets for specific studies. From the first 200 galaxies observed by CALIFA survey in its two configurations, we present the two-dimensional kinematic view of the 177 galaxies satisfaying a gas content/detection threshold. Methods. After removing the stellar contribution, we used the cross-correlation technique to obtain the radial velocity of the dominant gaseous component for each spectrum in the CALIFA data cubes for different emission lines (namely, [O ii] λλ3726, 3729, [OIII] λλ4959, 5007, Hα+[N II] λλ6548, 6584, and [SII]λλ6716, 6730). The main kinematic parameters measured on the plane of the sky were directly derived from the radial velocities with no assumptions on the internal prevailing motions. Evidence of the presence of several gaseous components with different kinematics were detected by using [OIII] λλ4959, 5007 emission line profiles. Results. At the velocity resolution of CALIFA, most objects in the sample show regular velocity fields, although the ionized-gas kinematics are rarely consistent with simple coplanar circular motions. Thirty-five percent of the objects present evidence of a displacement between the photometric and kinematic centers larger than the original spaxel radii. Only 17% of the objects in the sample exhibit kinematic lopsidedness when comparing receding and approaching sides of the velocity fields, but most of them are interacting galaxies exhibiting nuclear activity (AGN or LINER). Early-type (E+S0) galaxies in the sample present clear photometric-kinematic misaligments. There is evidence of asymmetries in the emission line profiles in 117 out of the 177 analyzed galaxies, suggesting the presence of kinematically distinct gaseous components located at different distances from the optical nucleus. The kinematic decoupling between the dominant and secondary component/s suggested by the observed asymmetries in the profiles can be characterized by a limited set of parameters. Conclusions. This work constitutes the first determination of the ionized gas kinematics of the galaxies observed in the CALIFA survey. The derived velocity fields, the reported kinematic distortions/peculiarities and the identification of the presence of several gaseous components in different regions of the objects might be used as additional criteria for selecting galaxies for specific studies. [ABSTRACT FROM AUTHOR]

We have combined observations of the Antennae galaxies from the radio interferometer ALMA (Atacama Large Millimeter/submillimeter Array) and from the optical interferometer GHαFaS (Galaxy Hα Fabry–Perot System). The two sets of observations have comparable angular and spectral resolutions, enabling us to identify 142 giant molecular clouds (GMCs) and 303 H II regions. We have measured, and compared, their basic physical properties (radius, velocity dispersion, luminosity). For the H II regions, we find two physical regimes, one for masses >105.4 M⊙ of ionized gas, where the gas density increases with gas mass, the other for masses <105.4 M⊙ of ionized gas, where the gas density decreases with gas mass. For the GMCs, we find, in contrast to previous studies in other galaxies over a generally lower mass range of clouds, that the gas density increases with the total gas mass, hinting at two regimes for these clouds if we consider both sources of data. We also find that the GMC mass function has a break at 106.7 M⊙. Using the velocity dispersion measurements, we claim that the difference between the regimes is the nature of the dominant binding force. For the regions in the lower mass range, the dominant force is the external pressure, while in the higher mass range it is the internal gravity of the clouds. In the regime where gravity is dominant, the star formation rate, derived from the dust-corrected Hα luminosity, increases super-linearly with the velocity dispersion, and the gas density increases with the gas mass. [ABSTRACT FROM AUTHOR]

We present 80 stellar and ionised gas velocity maps from the Calar Alto Legacy Integral Field Area (CALIFA) survey in order to characterise the kinematic orientation of non-interacting galaxies. The study of galaxies in isolation is a key step towards understanding how fast-external processes, such as major mergers, affect kinematic properties in galaxies. We derived the global and individual (projected approaching and receding sides) kinematic position angles (PAs) for both the stellar and ionised gas line-of-sight velocity distributions. When compared to the photometric PA, we find that morpho-kinematic differences are smaller than 22 degrees in 90% of the sample for both stellar and nebular components and that internal kinematic misalignments are generally smaller than 16 degrees. We find a tight relation between the global stellar and ionised gas kinematic PA consistent with circular-flow pattern motions in both components (~90% of the sample has differences smaller than 16 degrees). This relation also holds, generally in barred galaxies across the bar and galaxy disc scales. Our findings suggest that even in the presence of strong bars, both the stellar and the gaseous components tend to follow the gravitational potential of the disc. As a result, kinematic orientation can be used to assess the degree of external distortions in interacting galaxies. [ABSTRACT FROM AUTHOR]

The presence of double-peaked/multi-component emission-line profiles in the spectra of galaxies is commonly identified by visual inspection. However, the identification of complex emission-line profiles by eye is unlikely for large data bases such as the Sloan Digital Sky Survey (SDSS) or the integral field spectroscopy surveys of galaxies (e.g. Calar Alto Legacy Integral Field Area Survey or The Mapping Nearby Galaxies at APO). We describe a quick method involving a cross-correlation technique for detecting the presence of complex (double-peaked or multiple components) profiles in the spectra of galaxies, deriving simultaneously a first estimation of the velocity dispersions and radial velocities of the dominant gaseous component. We illustrate the proposed procedure with the well-known complex [O iii]λλ4959, 5007 profiles of the central region of NGC 1068. [ABSTRACT FROM AUTHOR]

ABSTRACT HH 223 is the optical counterpart of a larger scale H2 outflow, driven by the protostellar source VLA 2A, in L723. Its poorly collimated and rather chaotic morphology suggested Integral Field Spectroscopy (IFS) as an appropriate option to map the emission in order to derive the physical conditions and kinematics. Here we present new results based on IFS observations made with the INTEGRAL system at the William Herschel Telescope. The brightest knots of HH 223 (∼16 arcsec, ≃0.02 pc at a distance of 300 pc) were mapped with a single pointing in the spectral range 6200-7700 Å. We obtained emission-line intensity maps for Hα, [N ii] 6584 Å and [S ii] 6716, 6731 Å and explored the distribution of the excitation and electron density from [N ii]/Hα, [S ii]/Hα and [S ii] 6716/6731 line-ratio maps. Maps of the radial velocity field were obtained. We analysed the three-dimensional kinematics by combining the knot radial velocities derived from IFS data with the knot proper motions derived from multi-epoch narrow-band images. The intensity maps built from IFS data reproduced the morphology found in the narrow-band images well. We checked the results obtained from previous long-slit observations with those derived from IFS spectra extracted with a similar spatial sampling. At the positions intersected by the slit, the physical conditions and kinematics derived from IFS are compatible with those derived from long-slit data. In contrast, significant discrepancies were found when the results from long-slit data were compared with the ones derived from IFS spectra extracted at positions shifted a few arcsec from those intersected by the slit. This clearly revealed IFS observations as the best choice to obtain a reliable picture of the HH emission properties. [ABSTRACT FROM AUTHOR]

ABSTRACT We present the largest data base so far of atmospheric optical turbulence profiles [197 035 individual C2 N( h)] for an astronomical site, the Roque de los Muchachos Observatory (La Palma, Spain). This C2 N( h) data base was obtained through generalized SCIDAR observations at the 1-m Jacobus Kapteyn Telescope from 2004 February to 2009 August, obtaining useful data for 211 nights. The overestimation of the turbulence strength induced during the generalized SCIDAR data processing has been analysed for the different observational configurations. All the individual C2 N( h) have been recalibrated to compensate for the errors introduced during data treatment. Comparing the results from profiles before and after the recalibration, we analyse its impact on the calculation of relevant parameters for adaptive optics. [ABSTRACT FROM AUTHOR]

García-Lorenzo et al. presented a complete study of atmospheric parameters relevant for adaptive optics in relation to wind speed at the Teide Observatory (Tenerife, Canary Islands, Spain). The atmospheric parameters were derived by combining profiles derived from generalized-SCIDAR observations and wind vertical profiles from radiosondes. Later, Avila & Cuevas pointed out that the generalized-SCIDAR data processing leads an overstimation of the actual turbulence strength, showing that the error introduced strongly depends on the observational setup of the generalized-SCIDAR observations. Avila & Cuevas provided the exact expression of the error that can be applied to correct the retrieved profiles. Recently, García-Lorenzo & Fuensalida calculated the error induced during data processing for all the observational configurations of the generalized-SCIDAR observations obtained at the Teide Observatory, showing that these errors are significant for some setups. Following the procedure in Avila & Cuevas, García-Lorenzo & Fuensalida corrected the full data base of atmospheric turbulence profiles for Teide Observatory. Here we present the corrected atmospheric parameters and show the different relationships between atmospheric parameters and wind speed. We conclude that the results of García-Lorenzo et al. were not drastically affected by the errors introduced in the profiles in the generalized-SCIDAR data processing, and that the conclusions there are the same after the correction of the profiles and recalculation of the atmospheric parameters. [ABSTRACT FROM AUTHOR]

ABSTRACT The characterization of the optical turbulence structure at an astronomical site requires a proper data base of the refractive-index structure constant, . Our team has been obtaining generalized SCIntillation Detection and Ranging (SCIDAR) observations to monitor from 2002 November-2009 January at Teide Observatory (Tenerife, Canary Islands, Spain). The Teide data base includes useful data from 153 nights of generalized SCIDAR measurements obtained at the 1.5-m Calos Sánchez Telescope. The overestimation of the turbulence strength as a consequence of generalized SCIDAR data processing has been analysed for all double stars and analysis-plane combinations used in our observations. If this overestimation of the turbulence is not taken into account, the median total seeing and isoplanatic angle derived from the turbulence profiles in the data base are 0.70 and 2.47 arcsec, respectively. We have recalibrated all the derived , correcting for this overestimation. The statistical optical turbulence structure above Teide Observatory is derived by combining the 93 662 individual that constitute the data base at this site. More than 85 per cent of the total optical turbulence is concentrated in low-altitude layers (<5 km above sea level). The optical turbulence structure presents an evolution of the layers in both strength and altitude. Only the turbulence concentration at the observatory level shows a similar turbulence strength over a standard year. The median values of total seeing and isoplanatic angle of ε0= 0.64 arcsec and θ0= 2.83 arcsec demonstrate the excellent quality of the Teide Observatory astronomical site for the implementation of adaptive optics systems. [ABSTRACT FROM AUTHOR]

An analysis of the impact of seismic and volcanic activity has been carried out at selected astronomical sites, namely the observatories of El Teide (Tenerife, Canary Islands), Roque de los Muchachos (La Palma, Canary Islands), Mauna Kea (Hawaii) and Paranal (Chile), and the candidate site of Cerro Ventarrones (Chile). Hazard associated with volcanic activity is low or negligible at all sites, whereas seismic hazard is very high in Chile and Hawaii. The lowest geological hazard in both seismic and volcanic activity is found at Roque de los Muchachos observatory, on the island of La Palma. [ABSTRACT FROM AUTHOR]

HH 110 is a rather peculiar HerbigHaro object in Orion that originates due to the deflection of another jet (HH 270) by a dense molecular clump, instead of being directly ejected from a young stellar object. Here we present new results on the kinematics and physical conditions of HH 110 based on Integral Field Spectroscopy. The 3D spectral data cover the whole outflow extent (∼4.5 arcmin, ≃0.6 pc at a distance of 460 pc) in the spectral range 6500–7000 Å. We built emission-line intensity maps of Hα, [N ii] and [S ii] and of their radial velocity channels. Furthermore, we analysed the spatial distribution of the excitation and electron density from [N ii]/Hα, [S ii]/Hα and [S ii] 6716/6731 integrated line-ratio maps, as well as their behaviour as a function of velocity, from line-ratio channel maps. Our results fully reproduce the morphology and kinematics obtained from previous imaging and long-slit data. In addition, the integral field spectroscopy (IFS) data revealed, for the first time, the complex spatial distribution of the physical conditions (excitation and density) in the whole jet, and their behaviour as a function of the kinematics. The results here derived give further support to the more recent model simulations that involve deflection of a pulsed jet propagating in an inhomogeneous ambient medium. The IFS data give richer information than that provided by current model simulations or laboratory jet experiments. Hence, they could provide valuable clues to constrain the space parameters in future theoretical works. [ABSTRACT FROM AUTHOR]

We present measurements of the atmospheric water vapour content above the Roque de los Muchachos Observatory (ORM) obtained using the Global Positioning System (GPS). The GPS measurements have been evaluated by comparison with 940-nm radiometer observations. A statistical analysis of the GPS measurements points to the ORM as an observing site with suitable conditions for infrared observations, with a median column of precipitable water vapour (PWV) of 3.8 mm. PWV presents a clear seasonal behaviour, with winter and spring being the best seasons for infrared observations. The percentage of nights showing PWV values less than 3 mm is over 60 per cent in February, March and April. We have also estimated the temporal variability of water vapour content at the ORM. We present a summary of PWV statistical results at different astronomical sites, noting that these values are not directly comparable as a result of the differences in the techniques used to recorded the data. [ABSTRACT FROM AUTHOR]

Current projects for large telescopes demand a proper knowledge of atmospheric turbulence to design efficient adaptive optics systems in order to reach large Strehl ratios. However, the proper characterization of the turbulence above a particular site requires long-term monitoring. Because of the lack of long-term information on turbulence, high-altitude winds (in particular winds at the 200 mbar pressure level) were proposed as a parameter for estimating the total turbulence at a particular site, with the advantage of records of winds going back several decades. We present the first complete study of atmospheric adaptive optics parameters above the Teide Observatory (Canary Islands, Spain) in relation to wind speed. On-site measurements of profiles (more than 20 200 turbulence profiles) from G-SCIDAR (Generalized Scintillation Detection and Ranging) observations and wind vertical profiles from balloons have been used to calculate the seeing, the isoplanatic angle and the coherence time. The connection of these parameters to wind speeds at ground and at 200 mbar pressure level are shown and discussed. Our results confirm the well-known high quality of the Canary Islands astronomical observatories. [ABSTRACT FROM AUTHOR]

HH 262 is a group of emitting knots displaying an ‘hour-glass’ morphology in the Hα and [S ii] lines, located 3.5 arcmin to the north-east of the young stellar object L1551-IRS5, in Taurus. We present new results of the kinematics and physical conditions of HH 262 based on Integral Field Spectroscopy covering a field of 3 arcmin2, which includes all the bright knots in HH 262. These data show complex kinematics and significant variations in physical conditions over the mapped region of HH 262 on a spatial scale of ≤3 arcsec. A new result derived from the Integral Field Spectroscopy data is the weakness of the [N ii] emission (below detection limit in most of the mapped region of HH 262), including the brightest central knots. Our data reinforce the association of HH 262 with the redshifted lobe of the evolved molecular outflow L1551-IRS5. The interaction of this outflow with a younger one, powered by L1551 NE, around the position of HH 262 could give rise to the complex morphology and kinematics of HH 262. [ABSTRACT FROM AUTHOR]

Generalized-Scintillation Detection and Ranging (g-SCIDAR) has proven to be the most reliable and efficient technique for obtaining the vertical structure of the atmospheric turbulence through optical means. However, undesirable turbulence inside the telescope enclosure (dome and mirror seeing) is intermixed with the results. Processes for rejecting this contribution have been used indirectly when the vertical wind profiles are obtained. With a view to introducing the routine use of g-SCIDAR technique in multiconjugate adaptive optics applications, we propose a simple method, based on evenness properties with Fourier analysis, for rejecting the dome and mirror seeing in ( h) profiles. The method is suitable for implementation in real time and could furthermore be extended to other applications of form recognition, whenever certain conditions of symmetry are satisfied. [ABSTRACT FROM AUTHOR]

We present new results on the nature of the Herbig–Haro-like object 73 (HHL 73, also known as [G84b] 11) based on narrow-band CCD Hα and [S ii] images of the HHL 73 field, and integral field spectroscopy (IFS) and radio continuum observations at 3.6 cm covering the emission of the HHL 73 object. The CCD images allow us to resolve the HHL 73 comet-shaped morphology into two components and a collimated emission feature of ∼4 arcsec long, reminiscent of a microjet. The IFS spectra of HHL 73 showed emission lines characteristic of the spectra of Herbig–Haro objects. The kinematics derived for HHL 73 are complex. The profiles of the [S ii]λλ6717, 6731 Å lines were well fitted with a model of three Gaussian velocity components peaking at VLSR≃−100, −20 and +35 km s−1. We found differences among the spatial distribution of the kinematic components that are compatible with the emission from a bipolar outflow with two blueshifted (low- and high-velocity) components. Extended radio continuum emission at 3.6 cm was detected showing a distribution in close agreement with the HHL 73 redshifted gas. From the results discussed here, we propose HHL 73 to be a true HH object. IRAS 21432+4719, offset 30-arcsec north-east from the HHL 73 apex, is the most plausible candidate to be driving HHL 73, although the evidence is not conclusive. [ABSTRACT FROM AUTHOR]

The characteristics of ionized and H i gas in the peculiar star/cluster complex in NGC 6946, obtained with the 6-m telescope (BTA) Special Astrophysical Observatory Russian Academy of Sciences (RAS), the Gemini North telescope, and the Westerbork Synthesis Radio Telescope, are presented. The complex is unusual as hosting a super star cluster, the most massive known in an apparently non-interacting giant galaxy. It contains a number of smaller clusters and is bordered by a sharp C-shaped rim. We found that the complex is additionally unusual in having peculiar gas kinematics. The velocity field of the ionized gas reveals a deep oval minimum, ∼300 pc in size, centred 7 arcsec east of the supercluster. The Vr of the ionized gas in the dip centre is 100 km s−1 lower than in its surroundings, and emission lines within the dip appear to be shock-excited. This dip is near the centre of an H i hole and a semi-ring of H ii regions. The H i (and less certainly, H ii) velocity fields reveal expansion, with the velocity reaching ∼30 km s−1 at a distance about 300 pc from the centre of expansion, which is near the deep minimum position. The superstar cluster is at the western rim of the minimum. The sharp western rim of the whole complex is plausibly a manifestation of a regular dust arc along the complex edge. Different hypotheses about the complex and the Vr depression's origins are discussed, including a high-velocity H i cloud/dark minihalo impact, a blue compact dwarf galaxy merging, and a gas outflow due to release of energy from the supercluster stars. [ABSTRACT FROM AUTHOR]

We describe a new method involving wavelet transforms for deriving the wind velocity associated with atmospheric turbulent layers from Generalized SCIDAR measurements. The algorithm analyses the cross-correlation of a series of scintillation patterns separated by lapses of Δ t, 2Δ t, 3Δ t, 4Δ t and 5Δ t using wavelet transforms. Wavelet analysis provides the position, direction and altitude of the different turbulent layers detected in each cross-correlation. The comparison and consistency of the turbulent-layer displacements in consecutive cross-correlations allow the determination of their velocities and avoid misidentifications associated with noise and/or overlapping layers. To validate the algorithm, we have compared the velocity of turbulent layers derived on four nights with the wind vertical profile provided by balloon measurements. The software is fully automated and is able to analyse huge amounts of Generalized SCIDAR measurements. [ABSTRACT FROM AUTHOR]

High-altitude wind speeds have been adopted as a parameter for astronomical site selection based on the relationship found at the Paranal and Cerro Pachón sites between the average velocity of the turbulence (V0) and winds at the 200-mbar pressure level (V200). Although this relationship has not been checked at any other site in the world and a connection between image quality andV200 has not been proven anywhere, high-altitude wind speed (V200) is a parameter for checking the suitability of sites for adaptive optics and surveying potential sites for extremely large telescopes.We present comprehensive and reliable statistics of high-altitude wind speeds and the tropospheric flows at the location of five important astronomical observatories. We have used the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) Reanalysis data base to collect wind data at nine tropospheric pressure levels for the five selected sites. For comparison and validation of the data from the climate diagnostic model, we have also obtained wind profiles from radiosonde stations. The degrees of correlation found indicate a high level of significance between NCEP/NCAR Reanalysis and balloon data bases, pointing to NCEP/NCAR Reanalysis as a useful data base for site characterization.Statistical analysis exclusively of high-altitude winds points to La Palma as the most suitable site for adaptive optics, with a mean value of 22.13 m s−1 at the 200-mbar pressure level. La Silla is at the bottom of the ranking, with the largest average value 200 mbar wind speed (33.35 m s−1). We have found a clear annual periodicity of high-altitude winds for the five sites under study.We have also explored the connection of high- to low-altitude atmospheric winds as a first approach of the linear relationship between the average velocity of the turbulence and high-altitude winds. We may conclude that high- and low-altitude winds show good linear relationships at the five selected sites. The highest correlation coefficients correspond to Paranal and San Pedro Mártir, while La Palma and La Silla show similar high- to low-altitude wind connection. Mauna Kea shows the smallest degree of correlation, which suggests a weaker linear relationship. Our results support the idea of high-altitude winds as a parameter for ranking astronomical sites in terms of their suitability for adaptive optics, although we have no evidence for adopting the same linear coefficient at different sites. The final value of this linear coefficient at a particular site could drastically change the interpretation of high-altitude wind speeds as a direct parameter for site characterization. [ABSTRACT FROM AUTHOR]

High-altitude wind has been recently proposed as an important parameter to be taken into account for astronomical site selection. We present here comprehensive and reliable statistics for wind speeds at the 200 mbar ( v200 hereafter) pressure level (approximately 12 km above the Canary Islands) based on long-term climate diagnostics archive and balloon data. The results presented in this paper demonstrate the remarkably good behaviour of the high-altitude wind above the Canarian archipelago, with low mean values of (22.12 m s−1 above the Roque de los Muchachos Observatory, hereafter ORM) and provide independent confirmation of the potential of the ORM and the Teide Observatory (OT) for adaptive optics. A comparison of values from a climatological data base and in situ measurements with radiosondes launched from Santa Cruz de Tenerife reveals an excellent level of agreement, which lends support to the claim that climate diagnostic measurements provide a useful tool for astronomical site assessment, although a rigorous control of data quality, analysis and cross comparison needs to be performed before the method becomes extensively used. Moreover, the correlation of the results for La Palma and Tenerife confirms the homogeneity of the Canarian sky at the tropopause level. The analysis of frequency and variability of led us to propose a seasonal periodicity of v200. [ABSTRACT FROM AUTHOR]

Integral field spectroscopy has been obtained for the nuclear regions of three large, well-studied, early-type galaxies. From these spectra we have obtained line-strength maps for about 20 absorption lines, mostly belonging to the Lick system. An extensive comparison with multilenslet spectroscopy shows that accurate kinematic maps can be obtained, and also reproducible line-strength maps. Comparison with long-slit spectroscopy also produces good agreement. We show that Mg is enhanced with respect to Fe in the inner disc of one of the three galaxies studied, the Sombrero. [Mg/Fe] there is larger than in the rest of the bulge. The large values of Mg/Fe in the central disc are consistent with the centres of other early-type galaxies, and not with large discs, like the disc of our Galaxy, where [Mg/Fe] ∼0. We confirm with this observation a recent result of Worthey: that Mg/Fe is determined only by the central kinetic energy, or escape velocity, of the stars, and not by the formation time-scale of the stars. A stellar population analysis using the models of Vazdekis et al. shows that our observed Hγ agrees well with what is predicted based on the other lines. Given the fact that Hβ is often contaminated by emission lines, we confirm the statement of Worthey & Ottaviani, Kuntschner & Davies and others that if one tries to measure ages of galaxies, Hγ is a much better index to use than Hβ. Using the line strength of the Ca ii IR triplet as an indicator of the abundance of Ca, we find that Ca follows Fe, and not Mg, in these galaxies. This is peculiar, given the fact that Ca is an α element. Finally, by combining the results of this paper with those of Vazdekis et al., we find that the line-strength gradients in the three galaxies are primarily caused by variations in metallicity. [ABSTRACT FROM AUTHOR]

We have combined observations of the Antennae galaxies from the radio interferometer ALMA and from the optical interferometer GHαFaS (Galaxy Hα Fabry-Perot System). The two sets of observations have comparable angular and spectral resolutions, enabling us to identify 142 giant molecular clouds (GMCs) and 303 Hii regions. We have measured, and compared, their basic physical properties (radius, velocity dispersion, luminosity). We study the mass functions of Hii regions and GMCs, where a double population of Hii regions due to a double population of GMCs is found. Using the velocity dispersion measurements, we claim that the difference between the regimes is the nature of the dominant binding force. For the regions in the lower mass range, the dominant force is the external pressure, while in the higher mass range it is the internal gravity of the clouds. We have applied the same method to similar observations (GHαFaS & ALMA) of Arp 236 and NGC 1614 finding similar results. [ABSTRACT FROM PUBLISHER]

We have observed 12 interacting galaxies using the Fabry-Perot interferometer GHαFaS (Galaxy Hα Fabry-Perot system) on the 4.2m William Herschel Telescope (La Palma). We have extracted the physical properties (sizes, Hα luminosity and velocity dispersion) of 236 HII regions for the full sample of interacting galaxies. We have derived the physical properties of 664 HII regions for a sample of 28 isolated galaxies observed with the same instrument in order to compare both populations of HII regions, finding that there are brighter and denser star forming regions in the interacting galaxies compared with the isolated galaxies sample. [ABSTRACT FROM PUBLISHER]