168 research outputs found

    MUSE crowded field 3D spectroscopy in NGC 300 III. Characterizing extremely faint HII regions and diffuse ionized gas

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    There are known differences between the physical properties of HII and diffuse ionized gas (DIG), but most of the studied regions in the literature are relatively bright. We compiled a faint sample of 390 HII regions with median log10Hα\log_{10}H\alpha=34.7 in the spiral galaxy NGC300, derived their physical properties in terms of metallicity, density, extinction, and kinematics, and performed a comparative analysis of the properties of the DIG. We used MUSE data of nine fields in NGC300, covering a galactocentric distance of zero to ~450 arcsec (~4 projected kpc), including spiral arm and inter-arm regions. We binned the data in dendrogram leaves and extracted all strong nebular emission lines. We identified HII and DIG regions and compared their electron densities, metallicity, extinction, and kinematic properties. We also tested the effectiveness of unsupervised machine-learning algorithms in distinguishing between the HII and DIG regions. The gas density in the HII and DIG regions is close to the low-density limit in all fields. The average velocity dispersion in the DIG is higher than in the HII regions, which can be explained by the DIG being 1.8 kK hotter than HII gas. The DIG manifests a lower ionization parameter than HII gas, and the DIG fractions vary between 15-77%, with strong evidence of a contribution by hot low-mass evolved stars and shocks to the DIG ionization. Most of the DIG is consistent with no extinction and an oxygen metallicity that is indistinguishable from that of the HII gas.We observe a flat metallicity profile in the central region, without a sign of a gradient. The differences between extremely faint HII and DIG regions follow the same trends and correlations as their much brighter cousins. HII and DIG are so heterogeneous, however, that the differences within each class are larger than the differences between the two classes.Comment: Accepted in A&

    SEOM clinical guidelines for the treatment of head and neck cancer (2017)

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    Head and neck cancer (HNC) is defined as malignant tumours located in the upper aerodigestive tract and represents 5% of oncologic cases in adults in Spain. More than 90% of these tumours have squamous histology. In an effort to incorporate evidence obtained since 2013 publication, Spanish Society of Medical Oncology (SEOM) presents an update of HNC diagnosis and treatment guideline. The eighth edition of TNM classification, published in January 2017, introduces important changes for p16-positive oropharyngeal tumours, for lip and oral cavity cancer and for N3 category. In addition, there are new data about induction chemotherapy and the role of immunotherapy in HNC

    The MUSE-Wide survey: Three-dimensional clustering analysis of Lyman-α\alpha emitters at 3.3<z<63.3<z<6

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    We present an analysis of the spatial clustering of 695 Lyα\alpha-emitting galaxies (LAE) in the MUSE-Wide survey. All objects have spectroscopically confirmed redshifts in the range 3.3<z<63.3<z<6. We employ the K-estimator of Adelberger et al. (2005), adapted and optimized for our sample. We also explore the standard two-point correlation function approach, which is however less suited for a pencil-beam survey such as ours. The results from both approaches are consistent. We parametrize the clustering properties by, (i) modelling the clustering signal with a power law (PL), and (ii) adopting a Halo Occupation Distribution (HOD) model. Applying HOD modeling, we infer a large-scale bias of bHOD=2.800.38+0.38b_{\rm{HOD}}=2.80^{+0.38}_{-0.38} at a median redshift of the number of galaxy pairs zpair3.82\langle z_{\rm pair}\rangle\simeq3.82, while the PL analysis results in bPL=3.030.52+1.51b_{\rm{PL}}=3.03^{+1.51}_{-0.52} (r0=3.600.90+3.10  h1r_0=3.60^{+3.10}_{-0.90}\;h^{-1}Mpc and γ=1.300.45+0.36\gamma=1.30^{+0.36}_{-0.45}). The implied typical dark matter halo (DMH) mass is log(MDMH/[h1M])=11.340.27+0.23\log(M_{\rm{DMH}}/[h^{-1}\rm{M}_\odot])=11.34^{+0.23}_{-0.27}. We study possible dependencies of the clustering signal on object properties by bisecting the sample into disjoint subsets, considering Lyα\alpha luminosity, UV absolute magnitude, Lyα\alpha equivalent width, and redshift as variables. We find a suggestive trend of more luminous Lyα\alpha emitters residing in more massive DMHs than their lower Lyα\alpha luminosity counterparts. We also compare our results to mock LAE catalogs based on a semi-analytic model of galaxy formation and find a stronger clustering signal than in our observed sample. By adopting a galaxy-conserving model we estimate that the LAEs in the MUSE-Wide survey will typically evolve into galaxies hosted by halos of log(MDMH/[h1M])13.5\log(M_{\rm{DMH}}/[h^{-1}\rm{M}_\odot])\approx13.5 at redshift zero, suggesting that we observe the ancestors of present-day galaxy groups.Comment: Accepted for publication in A&A. 22 pages, 20 figures, 4 table

    Equivalent widths of Lyman α\alpha emitters in MUSE-Wide and MUSE-Deep

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    The aim of this study is to better understand the connection between the Lyman α\alpha rest-frame equivalent width (EW0_0) and spectral properties as well as ultraviolet (UV) continuum morphology by obtaining reliable EW0_0 histograms for a statistical sample of galaxies and by assessing the fraction of objects with large equivalent widths. We used integral field spectroscopy from MUSE combined with broad-band data from the Hubble Space Telescope (HST) to measure EW0_0. We analysed the emission lines of 19201920 Lyman α\alpha emitters (LAEs) detected in the full MUSE-Wide (one hour exposure time) and MUSE-Deep (ten hour exposure time) surveys and found UV continuum counterparts in archival HST data. We fitted the UV continuum photometric images using the Galfit software to gain morphological information on the rest-UV emission and fitted the spectra obtained from MUSE to determine the double peak fraction, asymmetry, full-width at half maximum, and flux of the Lyman α\alpha line. The two surveys show different histograms of Lyman α\alpha EW0_0. In MUSE-Wide, 20%20\% of objects have EW0>240_0 > 240 \r{A}, while this fraction is only 11%11\% in MUSE-Deep and 16%\approx 16\% for the full sample. This includes objects without HST continuum counterparts (one-third of our sample), for which we give lower limits for EW0_0. The object with the highest securely measured EW0_0 has EW0=589±193_0=589 \pm 193 \r{A} (the highest lower limit being EW0=4464_0=4464 \r{A}). We investigate the connection between EW0_0 and Lyman α\alpha spectral or UV continuum morphological properties. The survey depth has to be taken into account when studying EW0_0 distributions. We find that in general, high EW0_0 objects can have a wide range of spectral and UV morphological properties, which might reflect that the underlying causes for high EW0_0 values are equally varied. (abridged)Comment: 28 pages, 21 + 1 figures, 7 + 1 tables, accepted for publication in A&

    NGDEEP Epoch 1: Spatially Resolved Hα\alpha Observations of Disk and Bulge Growth in Star-Forming Galaxies at zz \sim 0.6-2.2 from JWST NIRISS Slitless Spectroscopy

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    We study the Hα\alpha equivalent width, EW(Hα\alpha), maps of 19 galaxies at 0.6<z<2.20.6 < z < 2.2 in the Hubble Ultra Deep Field (HUDF) derived from NIRISS slitless spectroscopy as part of the Next Generation Deep Extragalactic Exploratory Public (NGDEEP) Survey. Our galaxies mostly lie on the star-formation main sequence with a stellar mass range of 1091011M\mathrm{10^9 - 10^{11} M_\odot}, and are therefore characteristic of "typical" star-forming galaxies at these redshifts. Leveraging deep HST and JWST broad-band images, spanning 0.4-4 μ\mum, we perform spatially-resolved fitting of the spectral energy distributions (SEDs) for these galaxies and construct specific star formation rate (sSFR) and stellar-mass-weighted age maps. We compare these to the EW(Hα\alpha) maps with a spatial resolution of \sim1 kpc. The pixel-to-pixel EW(Hα\alpha) increases with increasing sSFR and with decreasing age, with the average trend slightly different from the relations derived from integrated fluxes of galaxies from the literature. Quantifying the radial profiles of EW(Hα\alpha), sSFR, and age, the majority (84%) of galaxies show positive EW(Hα\alpha) gradients, positive sSFR gradients, and negative age gradients, in line with the the inside-out quenching scenario. A few galaxies (16%) show inverse (and flat) trends possibly due to merging or starbursts. Comparing the distributions of EW(Hα\alpha) and sSFR to the star formation history models as a function of galactocentric radius, the central region of galaxies (e.g., their bulges) have experienced, at least one, rapid star-formation episodes, which leads to the formation of bulge, while their outer regions (e.g., disks) grow in a more steady-state. These results demonstrate the ability to study resolved star formation in distant galaxies with JWST NIRISS.Comment: 22 pages, 11 figure

    JADES + JEMS: A Detailed Look at the Buildup of Central Stellar Cores and Suppression of Star Formation in Galaxies at Redshifts 3 < z < 4.5

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    We present a spatially resolved study of stellar populations in 6 galaxies with stellar masses M1010MM_*\sim10^{10}M_\odot at z3.7z\sim3.7 using 14-filter JWST/NIRCam imaging from the JADES and JEMS surveys. The 6 galaxies are visually selected to have clumpy substructures with distinct colors over rest-frame 360041003600-4100\r{A}, including a bright dominant stellar core that is close to their stellar-light centroids. With 23-filter photometry from HST to JWST, we measure the stellar-population properties of individual structural components via SED fitting using Prospector. We find that the central stellar cores are 2\gtrsim2 times more massive than the Toomre mass, indicating they may not form via in-situ fragmentation. The stellar cores have stellar ages of 0.40.70.4-0.7 Gyr that are similar to the timescale of clump inward migration due to dynamical friction, suggesting that they likely instead formed through the coalescence of giant stellar clumps. While they have not yet quenched, the 6 galaxies are below the star-forming main sequence by 0.20.70.2-0.7 dex. Within each galaxy, we find that the specific star formation rate is lower in the central stellar core, and the stellar-mass surface density of the core is already similar to quenched galaxies of the same masses and redshifts. Meanwhile, the stellar ages of the cores are either comparable to or younger than the extended, smooth parts of the galaxies. Our findings are consistent with model predictions of the gas-rich compaction scenario for the buildup of galaxies' central regions at high redshifts. We are likely witnessing the coeval formation of dense central cores, along with the onset of galaxy-wide quenching at z>3z>3.Comment: 32 pages, 16 figures, submitted to ApJ. Comments are welcom
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