Star formation driven galactic winds in UGC 10043 López-Cobá, C; Sánchez, S. F; Moiseev, A. V ...
Monthly notices of the Royal Astronomical Society,
06/2017, Letnik:
467, Številka:
4
Journal Article
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Abstract
We study the galactic wind in the edge-on spiral galaxy UGC 10043 with the combination of the CALIFA integral field spectroscopy data, scanning Fabry–Perot interferometry (FPI) and multiband ...photometry. We detect ionized gas in the extraplanar regions reaching a relatively high distance, up to ∼4 kpc above the galactic disc. The ionized gas line ratios (N ii/Hα, S ii/Hα and O i/Hα) present an enhancement along the semiminor axis, in contrast with the values found at the disc, where they are compatible with ionization due to H ii-regions. These differences, together with the biconic symmetry of the extra-planar ionized structure, make UGC 10043 a clear candidate for a galaxy with gas outflows ionizated by shocks. From the comparison of shock models with the observed line ratios, and the kinematics observed from the FPI data, we constrain the physical properties of the observed outflow. The data are compatible with a velocity increase of the gas along the extraplanar distances up to <400 km s−1 and the pre-shock density decreasing in the same direction. We also observe a discrepancy in the SFR estimated based on Hα (0.36 M⊙ yr−1) and that estimated with the cigale code, the latter being five times larger. Nevertheless, this SFR is still not enough to drive the observed galactic wind if we do not take into account the filling factor. We stress that the combination of the three techniques of observation with the models is a powerful tool to explore galactic winds in the Local Universe.
Genome studies of chronic lymphocytic leukemia (CLL) have revealed the remarkable subclonal heterogeneity of the tumors, but the clinical implications of this phenomenon are not well known. We ...assessed the mutational status of 28 CLL driver genes by deep-targeted next-generation sequencing and copy number alterations (CNA) in 406 previously untreated patients and 48 sequential samples. We detected small subclonal mutations (0.6-25% of cells) in nearly all genes (26/28), and they were the sole alteration in 22% of the mutated cases. CNA tended to be acquired early in the evolution of the disease and remained stable, whereas the mutational heterogeneity increased in a subset of tumors. The prognostic impact of different genes was related to the size of the mutated clone. Combining mutations and CNA, we observed that the accumulation of driver alterations (mutational complexity) gradually shortened the time to first treatment independently of the clonal architecture, IGHV status and Binet stage. Conversely, the overall survival was associated with the increasing subclonal diversity of the tumors but it was related to the age of patients, IGHV and TP53 status of the tumors. In conclusion, our study reveals that both the mutational complexity and subclonal diversity influence the evolution of CLL.
We have studied the radial structure of the stellar mass surface density (μ∗) and stellar population age as a function of the total stellar mass and morphology for a sample of 107 galaxies from the ...CALIFA survey. We applied the fossil record method based on spectral synthesis techniques to recover the star formation history (SFH), resolved in space and time, in spheroidal and disk dominated galaxies with masses from 109 to 1012 M⊙. We derived the half-mass radius, and we found that galaxies are on average 15% more compact in mass than in light. The ratio of half-mass radius to half-light radius (HLR) shows a dual dependence with galaxy stellar mass; it decreases with increasing mass for disk galaxies, but is almost constant in spheroidal galaxies. In terms of integrated versus spatially resolved properties, we find that the galaxy-averaged stellar population age, stellar extinction, and μ∗ are well represented by their values at 1 HLR. Negative radial gradients of the stellar population ages are present in most of the galaxies, supporting an inside-out formation. The larger inner (≤1 HLR) age gradients occur in the most massive (1011 M⊙) disk galaxies that have the most prominent bulges; shallower age gradients are obtained in spheroids of similar mass. Disk and spheroidal galaxies show negative μ∗ gradients that steepen with stellar mass. In spheroidal galaxies, μ∗ saturates at a critical value (~7 × 102 M⊙/pc2 at 1 HLR) that is independent of the galaxy mass. Thus, all the massive spheroidal galaxies have similar local μ∗ at the same distance (in HLR units) from the nucleus. The SFH of the regions beyond 1 HLR are well correlated with their local μ∗, and follow the same relation as the galaxy-averaged age and μ∗; this suggests that local stellar mass surface density preserves the SFH of disks. The SFH of bulges are, however, more fundamentally related to the total stellar mass, since the radial structure of the stellar age changes with galaxy mass even though all the spheroid dominated galaxies have similar radial structure in μ∗. Thus, galaxy mass is a more fundamental property in spheroidal systems, while the local stellar mass surface density is more important in disks.
The growth of galaxies is one of the key problems in understanding the structure and evolution of the universe and its constituents. Galaxies can grow their stellar mass by accretion of halo or ...intergalactic gas clouds, or by merging with smaller or similar mass galaxies. The gas available translates into a rate of star formation, which controls the generation of metals in the universe. The spatially resolved history of their stellar mass assembly has not been obtained so far for any given galaxy beyond the Local Group. Here we demonstrate how massive galaxies grow their stellar mass inside-out. We report the results from the analysis of the first 105 galaxies of the largest three-dimensional spectroscopic survey to date of galaxies in the local universe (CALIFA). We apply the fossil record method of stellar population spectral synthesis to recover the spatially and time resolved star formation history of each galaxy. We show, for the first time, that the signal of downsizing is spatially preserved, with both inner and outer regions growing faster for more massive galaxies. Further, we show that the relative growth rate of the spheroidal component, nucleus, and inner galaxy, which happened 5-7 Gyr ago, shows a maximum at a critical stellar mass ~7 x 10 super(10) M sub(middot in circle). We also find that galaxies less massive than ~10 super(10) M sub(middot in circle) show a transition to outside-in growth, thus connecting with results from resolved studies of the growth of low-mass galaxies.
Background and purpose
Plaque neovascularization is a hallmark of carotid plaque vulnerability. With contrast‐enhanced ultrasound (CEUS) it is possible to visualize plaque neovessels in vivo. Our aim ...was to determine if CEUS‐detected neovessels were associated with stroke recurrences in patients with a recent stroke and carotid atherosclerosis.
Methods
We conducted a prospective study of consecutive patients with a recent stroke and at least one atherosclerotic plaque in the internal carotid artery on the side consistent with symptoms. All of our patients underwent a carotid ultrasound examination including a CEUS study. Neovascularization was graded into three categories according to the extent of neovessels. During the follow‐up, we recorded stroke recurrences. A multivariable Cox regression analysis was performed to evaluate predictors of recurrence.
Results
We included 78 patients whose mean age was 74.3 ± 10.4 years. There were 29 (37.2%) patients with a low‐grade stenosis (<50%). The remainder presented moderate (50%–69%) or high‐grade (≥70%) stenosis. CEUS was not interpretable in 35.9% of the patients, mainly due to calcium shadows. We detected neovascularization in 80% of the plaques. After a median follow‐up of 14.1 (interquartile range, 9.5‐19.6) months, there were 15 (19.2%) stroke recurrences. In the Cox regression analysis, CEUS‐detected neovascularization was independently associated with the risk of stroke recurrence, even after adjusting for the degree of stenosis (hazard ratio, 6.57; 95% confidence interval, 1.66–26.01).
Conclusion
In patients with an anterior circulation ischaemic stroke and carotid atherosclerosis, plaque neovascularization detected with CEUS was an independent predictor of stroke recurrence.
Context. The star formation rate (SFR) is one of the main parameters used to analyze the evolution of galaxies through time. The need for recovering the light reprocessed by dust commonly requires ...the use of low spatial resolution far-infrared data. Recombination line luminosities provide an alternative, although uncertain dust-extinction corrections based on narrowband imaging or long-slit spectroscopy have traditionally posed a limit to their applicability. Integral field spectroscopy (IFS) is clearly the way to overcome this kind of limitation. Aims. We obtain integrated Hα, ultraviolet (UV) and infrared (IR)-based SFR measurements for 272 galaxies from the CALIFA survey at 0.005 <z< 0.03 using single-band and hybrid tracers. We aim to determine whether the extinction-corrected Hα luminosities provide a good measure of the SFR and to shed light on the origin of the discrepancies between tracers. Updated calibrations referred to Hα are provided. The well-defined selection criteria and large statistics allow us to carry out this analysis globally and split by properties, including stellar mass and morphological type. Methods. We derive integrated, extinction-corrected Hα fluxes from CALIFA, UV surface and asymptotic photometry from GALEX and integrated WISE 22 μm and IRAS fluxes. Results. We find that the extinction-corrected Hα luminosity agrees with the hybrid updated SFR estimators based on either UV or Hα plus IR luminosity over the full range of SFRs (0.03−20 M⊙ yr-1). The coefficient that weights the amount of energy produced by newly-born stars that is reprocessed by dust on the hybrid tracers, aIR, shows a large dispersion. However, this coefficient does not became increasingly small at high attenuations, as expected if significant highly-obscured Hα emission were missed, i.e., after a Balmer decrement-based attenuation correction is applied. Lenticulars, early-type spirals, and type-2 AGN host galaxies show smaller coefficients because of the contribution of optical photons and AGN to dust heating. Conclusions. In the local Universe, the Hα luminosity derived from IFS observations can be used to measure SFR, at least in statistically-significant, optically-selected galaxy samples, once stellar continuum absorption and dust attenuation effects are accounted for. The analysis of the SFR calibrations by galaxies properties could potentially be used by other works to study the impact of different selection criteria in the SFR values derived, and to disentangle selection effects from other physically motivated differences, such as environmental or evolutionary effects.
Seasonally dry tropical forests are distributed across Latin America and the Caribbean and are highly threatened, with less than 10% of their original extent remaining in many countries. Using 835 ...inventories covering 4660 species of woody plants, we show marked floristic turnover among inventories and regions, which may be higher than in other neotropical biomes, such as savanna. Such high floristic turnover indicates that numerous conservation areas across many countries will be needed to protect the full diversity of tropical dry forests. Our results provide a scientific framework within which national decision-makers can contextuaiize the floristic significance of their dry forest at a regional and continental scale.
We present an extended version of the spectral synthesis code starlight designed to incorporate both λ-by-λ spectra and photometric fluxes in the estimation of stellar population properties of ...galaxies. The code is tested with simulations and data for 260 galaxies culled from the Calar Alto Legacy Integral Field Area (CALIFA) survey, spatially matching the 3700–7000 Å optical data cubes to Galaxy Evolution Explorer (GALEX) near-ultraviolet (NUV) and far-ultraviolet (FUV) images. The sample spans E–Sd galaxies with masses from 109 to 1012 M⊙ and stellar populations all the way from star-forming to old, passive systems. Comparing results derived from purely optical fits with those which also consider the NUV and FUV data we find that the following. (1) The new code is capable of matching the input ultraviolet (UV) data within the errors while keeping the quality of the optical fit essentially unchanged. (2) Despite being unreliable predictors of the UV fluxes, purely optical fits yield stellar population properties which agree well with those obtained in optical+UV fits for nearly 90 per cent of our sample. (3) The addition of UV constraints has little impact on properties such as stellar mass and dust optical depth. Mean stellar ages and metallicities also remain nearly the same for most galaxies, the exception being low-mass, late-type galaxies, which become older and less enriched due to rearrangements of their youngest populations. (4) The revised ages are better correlated with observables such as the 4000 Å break index, and the NUV − r and u − r colours, an empirical indication that the addition of UV constraints helps mitigating the effects of age–metallicity–extinction degeneracies.
We present the single stellar population (SSP) synthesis Results of our new synthetic stellar atmosphere models library with a spectral sampling of 0.3 Å, covering the wavelength range from 3000 to ...7000 Å for a wide range of metallicities (twice solar, solar, half solar and 1/10 solar). The stellar library is composed of 1650 spectra computed with the latest improvements in stellar atmospheres. In particular, it incorporates non-local thermodynamic equilibrium (LTE) line-blanketed models for hot (Teff≥ 27 500 K), and LTE line-blanketed models (Phoenix) for cool (3000 ≤Teff≤ 4500 K) stars. Because of the high spectral resolution of this library, evolutionary synthesis models can be used to predict the strength of numerous weak absorption lines and the evolution of the profiles of the strongest lines over a wide range of ages. The SSP Results have been calculated for ages from 1 Myr to 17 Gyr using the stellar evolutionary tracks provided by the Geneva and Padova groups. For young stellar populations, our Results have a very detailed coverage of high-temperature stars with similar Results for the Padova and Geneva isochrones. For intermediate and old stellar populations, our Results, once degraded to a lower resolution, are similar to the ones obtained by other groups (limitations imposed by the stellar evolutionary physics notwidthstanding). The limitations and advantages of our models for the analysis of integrated populations are described. The full set of the stellar library and the evolutionary models are available for retrieval at the websites http://www.iaa.csic.es/~rosa and http://www.iaa.csic.es/~/sed@, or on request from the first two authors.
Dyssodia tagetiflora is known as ‘Tzaracata’ and ‘flor de muerto’. Recently, D. tagetiflora has been reported to have antioxidant activities in its polar extracts as well as insecticidal activities. ...Hyperoside (1), avicularin (2) and avicularin acetate (3) have been isolated previously. However, the temporary variation in glycoside flavonoids biosynthesis, as well as antibacterial and chemoprotective activities, have not been reported. The amount of 1, 2 and 3 in the different collections was characterized by HPLC-MS. Two new C-glycosides were characterized, quercetin-4’-methyl ether 6-C glucoside (A1) and quercetin-4’-methyl ether 8-C glucoside (A2), as well as 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-4-oxochromen-3-yl3,4,5-trihydroxyoxane-2,6-dicarboxylate (A3). This is the first report of the presence of C-C flavonoid glycosides compounds in the genus Dyssodia. Hyperoside was the majority compound at all collections. The methanolic extracts of August 2016 and October 2017 were active against Micrococcus luteus and Bacillus subtillis. The methanolic extract has chemoprotective effects because, when applied topically in SKH-1 mice, it decreases the severity of epidermal damage induced by acute exposure to ultraviolet radiation. In addition, cutaneous photocarcinogenesis was decreased in mice treated with the extract. The methanolic extract of D. tagetiflora has chemoprotective properties by decreasing the damage caused by acute and chronic exposure to UV in mice.
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•This is the first report of C-C flavonoid glycoside compounds in the genus Dyssodia.•Extracts containing A1 were active against Micrococcus luteus and Bacillus subtillis.•Extracts containing A1 and avicularin acetate had higher bactericide activity.•Methanolic extract of D. tagetiflora reduce UV radiation epidermal damage.•Cutaneous photocarcinogenesis was decreased in mice treated with this extract.
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