Shocked Gas in IRAS F17207-0014: ISM Collisions and Outflows

We combine optical and near-infrared AO-assisted integral field observations of the merging ULIRG IRAS F17207-0014 from the Wide-Field Spectrograph (WiFeS) and Keck/OSIRIS. The optical emission line ratios [N II]/H$\alpha$, [S II]/H$\alpha$, and [O I]/H$\alpha$ reveal a mixing sequence of shocks present throughout the galaxy, with the strongest contributions coming from large radii (up to 100% at $\sim$5 kpc in some directions), suggesting galactic-scale winds. The near-infrared observations, which have approximately 30 times higher spatial resolution, show that two sorts of shocks are present in the vicinity of the merging nuclei: low-level shocks distributed throughout our field-of-view evidenced by an H$_{2}$/Br$\gamma$ line ratio of $\sim$0.6-4, and strong collimated shocks with a high H$_{2}$/Br$\gamma$ line ratio of $\sim$4-8, extending south from the two nuclear disks approximately 400 pc ($\sim$0.5 arcsec). Our data suggest that the diffuse shocks are caused by the collision of the interstellar media associated with the two progenitor galaxies and the strong shocks trace the base of a collimated outflow coming from the nucleus of one of the two disks.Comment: accepted to MNRA

Long-term safety and efficacy of trifarotene 50 μg/g cream, a first-in-class RAR-γ selective topical retinoid, in patients with moderate facial and truncal acne.

BackgroundTreatment for both facial and truncal acne has not sufficiently been studied.ObjectivesTo evaluate the long-term safety and efficacy of trifarotene in both facial and truncal acne.MethodsIn a multicentre, open-label, 52-week study, patients with moderate facial and truncal acne received trifarotene 50 μg/g cream (trifarotene). Assessments included local tolerability, safety, investigator and physician's global assessments (IGA, PGA) and quality of life (QOL). A validated QOL questionnaire was completed by the patient at Baseline, Week 12, 26 and 52/ET.ResultsOf 453 patients enrolled, 342 (75.5%) completed the study. Trifarotene-related treatment-emergent adverse events (TEAEs) were reported in 12.6% of patients, and none was serious. Most related TEAEs were cutaneous and occurred during the first 3 months. Signs and symptoms of local tolerability were mostly mild or moderate and severe signs, and symptoms were reported for 2.2% to 7.1% of patients for the face and 2.5% to 5.4% for the trunk. Local irritation increased during the first week of treatment on the face and up to Weeks 2 to 4 on the trunk with both decreasing thereafter. At Week 12, IGA and PGA success rates were 26.6% and 38.6%, respectively. Success rates increased to 65.1% and 66.9%, respectively at Week 52. Overall success (both IGA and PGA success in the same patient) was 57.9% at Week 52. At Week 52 visit, 92/171 (53.8%) patients who had completed their assessments had scores from 0 to 1 (i.e. no effect of acne on their QOL) vs. 47/208 (22.6%) patients at Baseline visit.ConclusionIn this 52-week study, trifarotene was safe, well tolerated and effective in moderate facial and truncal acne

Abundances in bulge stars from high-resolution, near-IR spectra I. The CNO elements observed during the science verification of CRIRES at VLT

The formation and evolution of the Milky Way bulge is not yet well understood and its classification is ambiguous. Constraints can, however, be obtained by studying the abundances of key elements in bulge stars. The aim of this study is to determine the chemical evolution of CNO, and a few other elements in stars in the Galactic bulge, and to discuss the sensitivities of the derived abundances from molecular lines. High-resolution, near-IR spectra in the H band were recorded using VLT/CRIRES. Due to the high and variable visual extinction in the line-of-sight towards the bulge, an analysis in the near-IR is preferred. The CNO abundances can all be determined simultaneously from the numerous molecular lines in the wavelength range observed. The three giant stars in Baade's window presented here are the first bulge stars observed with CRIRES. We have especially determined the CNO abundances, with uncertainties of less than 0.20 dex, from CO, CN, and OH lines. Since the systematic uncertainties in the derived CNO abundances due to uncertainties in the stellar fundamental parameters, notably Teff, are significant, a detailed discussion of the sensitivities of the derived abundances is included. We find good agreement between near-IR and optically determined O, Ti, Fe, and Si abundances. Two of our stars show a solar [C+N/Fe], suggesting that these giants have experienced the first dredge-up and that the oxygen abundance should reflect the original abundance of the giants. The two giants fit into the picture, in which there is no significant difference between the O abundance in bulge and thick-disk stars. Our determination of the S abundances is the first for bulge stars. The high [S/Fe] values for all the stars indicate a high star-formation rate in an early phase of the bulge evolution.Comment: Accepted by A&

Mid-Infrared Properties of Luminous Infrared Galaxies II: Probing the Dust and Gas Physics of the GOALS Sample

The Great Observatories All-Sky LIRG Survey (GOALS) is a comprehensive, multiwavelength study of luminous infrared galaxies (LIRGs) in the local universe. Here we present the results of a multi-component, spectral decomposition analysis of the low resolution mid-IR Spitzer IRS spectra from 5-38um of 244 LIRG nuclei. The detailed fits and high quality spectra allow for characterization of the individual PAH features, warm molecular hydrogen emission, and optical depths for silicate dust grains and water ices. We find that starbursting LIRGs, which make up the majority of GOALS, are very consistent in their MIR properties (i.e. tau_9.7um, tau_ice, neon line and PAH feature ratios). However, as their PAH EQW decreases, usually an indicator of an increasingly dominant AGN, LIRGs cover a larger spread in these MIR parameters. The contribution from PAHs to the total L(IR) in LIRGs varies from 2-29% and LIRGs prior to their first encounter show higher L(PAH)/L(IR) ratios on average. We observe a correlation between the strength of the starburst (IR8) and the PAH fraction at 8um but not with the 7.7 to 11.3 PAH ratio, suggesting the fractional PDR emission, and not the overall grain properties, is associated with the rise in IR8 for galaxies off the starburst main sequence. We detect crystalline silicate features in 6% of the sample but only in the most obscured sources (s_9.7um < -1.24). Ice absorption features are observed in 11% (56%) of GOALS LIRGs (ULIRGs). Most GOALS LIRGs have L(H2)/L(PAH) ratios elevated above those observed for normal star-forming galaxies and exhibit a trend for increasing L(H2)/L(PAH) ratio with increasing L(H2). While star formation appears to be the dominant process responsible for exciting the H2 in most of the GOALS galaxies, a subset of LIRGs (10%) show excess H2 emission that is inconsistent with PDR models and may be excited by shocks or AGN-induced outflows.Comment: 21 pages with 20 figures plus 2 table

Strong Far-IR Cooling Lines, Peculiar CO Kinematics and Possible Star Formation Suppression in Hickson Compact Group 57

We present [C II] and [O I] observations from Herschel and CO(1-0) maps from the Combined Array for{\dag} Research in Millimeter Astronomy (CARMA) of the Hickson Compact Group HCG 57, focusing on the galaxies HCG 57a and HCG 57d. HCG 57a has been previously shown to contain enhanced quantities of warm molecular hydrogen consistent with shock and/or turbulent heating. Our observations show that HCG 57d has strong [C II] emission compared to L$_{\rm FIR}$ and weak CO(1-0), while in HCG 57a, both the [C II] and CO(1-0) are strong. HCG 57a lies at the upper end of the normal distribution of [C II]/CO and [C II]/FIR ratios, and its far-IR cooling supports a low density warm diffuse gas that falls close to the boundary of acceptable PDR models. However, the power radiated in the [C II] and warm H$_2$ emission have similar magnitudes, as seen in other shock-dominated systems and predicted by recent models. We suggest that shock-heating of the [C II] is a viable alternative to photoelectric heating in violently disturbed diffuse gas. The existence of shocks is also consistent with peculiar CO kinematics in the galaxy, indicating highly non-circular motions are present. These kinematically disturbed CO regions also show evidence of suppressed star formation, falling a factor of 10-30 below normal galaxies on the Kennicutt-Schmidt relation. We suggest that the peculiar properties of both galaxies are consistent with a highly dissipative off-center collisional encounter between HCG 57d and 57a, creating ring-like morphologies in both systems. Highly dissipative gas-on-gas collisions may be more common in dense groups because of the likelihood of repeated multiple encounters. The possibility of shock-induced SF suppression may explain why a subset of these HCG galaxies have been found previously to fall in the mid-infrared green valley.Comment: ApJ accepted, 16 pages, 12 figures, 3 table

Shocked gas in IRAS F17207-0014: ISM collisions and outflows

We combine optical and near-infrared adaptive optics-assisted integral field observations of the merging ultraluminous infrared galaxies IRAS F17207-0014 from the Wide-Field Spectrograph and Keck/OH-Suppressing Infra-Red Imaging Spectrograph (OSIRIS). The optical emission line ratios [NII]/Hα, [SII]/Hα, and [O I]/Hα reveal a mixing sequence of shocks present throughout the galaxy, with the strongest contributions coming from large radii (up to 100 per cent at ~5 kpc in some directions), suggesting galactic-scale winds. The near-infrared observations, which have approximately 30 times higher spatial resolution, show that two sorts of shocks are present in the vicinity of the merging nuclei: low-level shocks distributed throughout our field-of-view evidenced by an H2/Brγ line ratio of ~0.6-4, and strong collimated shocks with a high H2/Brγ line ratio of ~4-8, extending south from the two nuclear discs approximately 400 pc (~0.5 arcsec). Our data suggest that the diffuse shocks are caused by the collision of the interstellar media associated with the two progenitor galaxies and the strong shocks trace the base of a collimated outflow coming from the nucleus of one of the two discs

Star-forming Clumps in Local Luminous Infrared Galaxies

We present HST narrowband near-infrared imaging of Paα and Paβ emission of 48 local luminous infrared galaxies (LIRGs) from the Great Observatories All-Sky LIRG Survey. These data allow us to measure the properties of 810 spatially resolved star-forming regions (59 nuclei and 751 extranuclear clumps) and directly compare their properties to those found in both local and high-redshift star-forming galaxies. We find that in LIRGs the star-forming clumps have radii ranging from ~90 to 900 pc and star formation rates (SFRs) of ~1 × 10⁻³ to 10 M⊙ yr⁻¹, with median values for extranuclear clumps of 170 pc and 0.03 M⊙ yr⁻¹. The detected star-forming clumps are young, with a median stellar age of 8.7 Myr, and have a median stellar mass of 5 × 10⁵ M ⊙. The SFRs span the range of those found in normal local star-forming galaxies to those found in high-redshift star-forming galaxies at z = 1–3. The luminosity function of the LIRG clumps has a flatter slope than found in lower-luminosity, star-forming galaxies, indicating a relative excess of luminous star-forming clumps. In order to predict the possible range of star-forming histories and gas fractions, we compare the star-forming clumps to those measured in the MassiveFIRE high-resolution cosmological simulation. The star-forming clumps in MassiveFIRE cover the same range of SFRs and sizes found in the local LIRGs and have total gas fractions that extend from 10% to 90%. If local LIRGs are similar to these simulated galaxies, we expect that future observations with ALMA will find a large range of gas fractions, and corresponding star formation efficiencies, among the star-forming clumps in LIRGs

Discovery of the neutron radiative decay

The aim of this work is experimental discovery and research of a rare neutron mode, the radiative beta-decay, where a new particle, the radiative gamma-quantum, is formed along with the expected decay products beta-electron, recoil proton and antineutrino. The discovery of this rare neutron decay mode was conducted through identification of triple coincidences events: simultaneous registration of beta electron, proton and radiative gamma-quantum. The ordinary neutron decay was registered by double coincidences of beta electron and recoil proton. The ratio of triple to double coincidences is connected with relative intensity of radiative neutron decay (branching ratio - B.R.) B.R. = (3.2+1.6)10-3 (with 90 % C.L. and in the gamma energy region greater than 35 keV), which we are the first in the world to measure during the second and third cycles on FRMII (TUM, Germany) in Summer 2005. This value of B.R. is consistent with standard electroweak theory.Comment: Corrected version of this paper was published in JETP Letters 83(1

An Abundance Analysis for Five Red Horizontal Branch Stars in the Extremely Metal Rich Globular Cluster NGC 6553

We provide a high dispersion line-by-line abundance analysis of five red HB stars in the extremely metal rich galactic globular cluster NGC 6553. These red HB stars are significantly hotter than the very cool stars near the tip of the giant branch in such a metal rich globular cluster and hence their spectra are much more amenable to an abundance analysis than would be the case for red giants. We find that the mean [Fe/H] for NGC 6553 is -0.16 dex, comparable to the mean abundance in the galactic bulge found by McWilliam & Rich (1994) and considerably higher than that obtained from an analysis of two red giants in this cluster by Barbuy etal (1999). The relative abundance for the best determined alpha process element (Ca) indicates an excess of alpha process elements of about a factor of two. The metallicity of NGC 6553 reaches the average of the Galactic bulge and of the solar neighborhood.Comment: 29 pages, 6 figures, accepted for publication in the Ap

SHOCKED POSTSTARBURST GALAXY SURVEY. II. the MOLECULAR GAS CONTENT and PROPERTIES of A SUBSET of SPOGs

We present CO(1–0) observations of objects within the Shocked POststarburst Galaxy Survey taken with the Institut de Radioastronomie Millimétrique 30 m single dish and the Combined Array for Research for Millimeter Astronomy interferometer. Shocked poststarburst galaxies (SPOGs) represent a transitioning population of galaxies, with deep Balmer absorption $({\mathrm{EW}}_{{\rm{H}}\delta }\gt 5\,{\mathring{\rm{A}}} )$, consistent with an intermediate-age (A-star) stellar population, and ionized gas line ratios inconsistent with pure star formation. The CO(1–0) subsample was selected from SPOGs detected by the Wide-field Infrared Survey Explorer with 22 μm flux detected at a signal-to-noise ratio (S/N) > 3. Of the 52 objects observed in CO(1–0), 47 are detected with S/N > 3. A large fraction (37%–46% ± 7%) of our CO-SPOG sample were visually classified as morphologically disrupted. The H2 masses detected were between ${10}^{8.7-10.8}$ ${M}_{\odot }$, consistent with the gas masses found in normal galaxies, though approximately an order of magnitude larger than the range seen in poststarburst galaxies. When comparing the 22 μm and CO(1–0) fluxes, SPOGs diverge from the normal star-forming relation, having 22 μm fluxes in excess of the relation by a factor of $\langle {\epsilon }_{{\rm{MIR}}}\rangle ={4.91}_{-0.39}^{+0.42}$, suggestive of the presence of active galactic nuclei (AGNs). The Na i D characteristics of CO-SPOGs show that it is likely that many of these objects host interstellar winds. Objects with large Na i D enhancements also tend to emit in the radio, suggesting possible AGN driving of neutral winds