67 research outputs found

    Physics of ULIRGs with MUSE and ALMA: The PUMA project: II. Are local ULIRGs powered by AGN: The subkiloparsec view of the 220 GHz continuum

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    We analyze new high-resolution (400 pc) ∌220 GHz continuum and CO(2–1) Atacama Large Millimeter Array (ALMA) observations of a representative sample of 23 local (z  1 for 70% of the sample. Therefore, this favors the presence of an obscured active galactic nucleus (AGN) in these objects that could dominate the LIR. We also classify the ULIRG nuclei in two groups: (a) compact nuclei (rcont < 120 pc) with high mid-infrared excess emission (ΔL6−20 Όm/LIR) found in optically classified AGN; and (b) nuclei following a relation with decreasing ΔL6−20 Όm/LIR for decreasing rcont. The majority, 60%, of the nuclei in interacting systems lie in the low-rcont end (<120 pc) of this relation, while this is the case for only 30% of the mergers. This suggests that in the early stages of the interaction, the activity occurs in a very compact and dust-obscured region while, in more advanced merger stages, the activity is more extended, unless an optically detected AGN is present. Approximately two-thirds of the nuclei have nuclear radiation pressures above the Eddington limit. This is consistent with the ubiquitous detection of massive outflows in local ULIRGs and supports the importance of the radiation pressure in the outflow launching process

    Physics of ULIRGs with MUSE and ALMA: PUMA IV. No tight relation between cold molecular outflow rates and AGN luminosities

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    We study molecular outflows in a sample of 25 nearby (z< 0.17, d<750 Mpc) ULIRG systems (38 individual nuclei) as part of the "Physics of ULIRGs with MUSE and ALMA" (PUMA) survey, using ~400 pc (0.1-1.0" beam FWHM) resolution ALMA CO(2-1) observations. We used a spectro-astrometry analysis to identify high-velocity (> 300 km/s) molecular gas disconnected from the galaxy rotation, which we attribute to outflows. In 77% of the 26 nuclei with log⁥LIR/L⊙>11.8\log L_{IR}/L_{\odot}>11.8, we identifid molecular outflows with an average vout=490v_{out}= 490 km/s, outflow masses 1−35×1071-35 \times 10^7 M⊙M_{\odot}, mass outflow rates M˙out=6−300\dot{M}_{out}=6-300 M⊙M_{\odot} yr−1^{-1}, mass-loading factors η=M˙out/SFR=0.1−1\eta = \dot{M}_{out}/SFR = 0.1-1, and an average outflow mass escape fraction of 45%. The majority of these outflows (18/20) are spatially resolved with radii of 0.2-0.9 kpc and have short dynamical times (tdyn=Rout/voutt_{dyn}=R_{out}/v_{out}) in the range 0.5-2.8 Myr. The outflow detection rate is higher in nuclei dominated by starbursts (SBs, 14/15=93%) than in active galactic nuclei (AGN, 6/11=55%). Outflows perpendicular to the kinematic major axis are mainly found in interacting SBs. We also find that our sample does not follow the M˙out\dot{M}_{out} versus AGN luminosity relation reported in previous works. In our analysis, we include a sample of nearby main-sequence galaxies (SFR = 0.3-17 M⊙M_{\odot} yr−1^{-1}) with detected molecular outflows from the PHANGS-ALMA survey to increase the LIRL_{IR} dynamic range. Using these two samples, we find a correlation between the outflow velocity and the SFR, as traced by LIRL_{IR} (vout∝SFR0.25±0.01)v_{out} \propto SFR^{0.25\pm0.01}), which is consistent with what was found for the atomic ionised and neutral phases. Using this correlation, and the relation between Mout/RoutM_{out}/R_{out} and voutv_{out}, we conclude that these outflows are likely momentum-driven.Comment: 27 pages, 23 figures; Appendix: 49 pages, 41 figures. Accepted for publication in Astronomy & Astrophysic

    Duality in spatially resolved star formation relations in local LIRGs

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    We analyse the star formation (SF) relations in a sample of 16 nearby luminous infrared galaxies (LIRGs) with more than 2800 regions defined on scales of 90 to 500 pc. We used ALMA to map the distribution of the cold molecular gas traced by the J = 2–1 line of CO and archival Paα HST/NICMOS imaging to trace the recent SF. In four objects we find two different branches in the Kennicutt-Schmidt relation at 90 pc scales, suggesting the existence of a duality in this relation. The two branches correspond to two different dynamical environments within each galaxy. One branch, which corresponds to the central region of these galaxies (90% of the regions are located at radii < 0.85 kpc), shows higher gas and SF rate surface densities with higher velocity dispersion. The other branch, which shows lower molecular gas and SF rate surface densities, corresponds to the more external disk regions (r ∌ 1 kpc). Despite the scatter, the SF efficiency of the galaxies with dual behaviour increases with increasing boundedness as measured by the b parameter (b≡ ÎŁH2/σ2 ∝ αvir−1). At larger spatial scales (250 and 500 pc), the duality disappears. The rest of the sample does not show evidence of this dual behaviour at any scale. © ESO 2022.M.S.G. acknowledges support from the Spanish Ministerio de EconomĂ­a y Competitividad through the grants BES-2016-078922, ESP2017-83197-P. L.C. and M.S.G. acknowledge support from the research project PID2019-106280GB-100. M.P.S. acknowledges support from the Comunidad de Madrid through the AtracciĂłn de Talento Investigador Grant 2018-T1/TIC-11035 and PID2019-105423GA-I00 (MCIU/AEI/FEDER,UE). A.A.-H. and S.G.-B. work was funded by grant PGC2018-094671-B-I00 funded by MCIN/AEI/ 10.13039/501100011033 and by ERDF A way of making Europe. S.G.B. acknowledges support from the research project PID2019-106027GA-C44 of the Spanish Ministerio de Ciencia e InnovaciĂłn. J.P.L. acknowledges support from PID2019-105423GA-I00. E.B. acknowledges the support from Comunidad de Madrid through the AtracciĂłn de Talento grant 2017-T1/TIC-5213. S.C. acknowledges financial support from the State Agency for Research of the Spanish MCIU through the ‘Centre of Excellence Severo Ochoa’ award to the Instituto de AstrofĂ­sica de AndalucĂ­a (SEV-2017-0709). A.L. acknowledges the support from Comunidad de Madrid through the AtracciĂłn de Talento Investigador Grant 2017-T1/TIC-5213, and PID2019-106280GB-I00 (MCIU/AEI/FEDER,UE) This paper makes use of the following ALMA data: ADS/JAO.ALMA#2017.1.00255.S, ADS/JAO.ALMA#2013.1.00271.S, ADS/JAO.ALMA#2013.1.00243.S, ADS/JAO.ALMA#2015.1.00714.S and ADS/JAO.ALMA#2017.1.00395.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan) and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.Peer reviewe

    The Galaxy Activity, Torus, and Outflow Survey (GATOS): III. Revealing the inner icy structure in local active galactic nuclei

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    We use JWST/MIRI MRS spectroscopy of a sample of six local obscured type 1.9/2 active galactic nuclei (AGN) to compare their nuclear mid-IR absorption bands with the level of nuclear obscuration traced by X-rays. This study is the first to use subarcsecond angular resolution data of local obscured AGN to investigate the nuclear mid-IR absorption bands with a wide wavelength coverage (4.9–28.1 ÎŒm). All the nuclei show the 9.7 ÎŒm silicate band in absorption. We compare the strength of the 9.7 and 18 ÎŒm silicate features with torus model predictions. The observed silicate features are generally well explained by clumpy and smooth torus models. We report the detection of the 6 ÎŒm dirty water ice band (i.e., a mix of water and other molecules such as CO and CO2) at subarcsecond scales (∌0.26″ at 6 ÎŒm; inner ∌50 pc) in a sample of local AGN with different levels of nuclear obscuration in the range log NHX-Ray (cm−2)∌22 − 25. We find good correlation between the 6 ÎŒm water ice optical depths and NHX-Ray. This result indicates that the water ice absorption might be a reliable tracer of the nuclear intrinsic obscuration in AGN. The weak water ice absorption in less obscured AGN (log NHX-ray (cm−2)â‰Č23.0 cm−2) might be related to the hotter dust temperature (> TsubH2O ∌ 110 K) expected to be reached in the outer layers of the torus due to their more inhomogeneous medium. Our results suggest it might be necessary to include the molecular content, such as H2O, aliphatic hydrocarbons (CH−), and more complex polycyclic aromatic hydrocarbon (PAH) molecules, in torus models to better constrain key parameters such as the torus covering factor (i.e., nuclear obscuration)

    The Galaxy Activity, Torus, and Outflow Survey (GATOS). III: Revealing the inner icy structure in local AGN

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    We use JWST/MIRI MRS spectroscopy of a sample of six local obscured type 1.9/2 active galactic nuclei (AGN) to compare their nuclear mid-IR absorption bands with the level of nuclear obscuration traced by X-rays. This study is the first to use sub-arcsecond angular resolution data of local obscured AGN to investigate the nuclear mid-IR absorption bands with a wide wavelength coverage (4.9-28.1 ÎŒ\mum). All the nuclei show the 9.7 ÎŒ\mum silicate band in absorption. We compare the strength of the 9.7 and 18 ÎŒ\mum silicate features with torus model predictions. The observed silicate features are generally well explained by clumpy and smooth torus models. We report the detection of the 6 ÎŒ\mum dirty water ice band (i.e., a mix of water and other molecules such as CO and CO2_2) at sub-arcsecond scales (∌\sim0.26 arcsec at 6 ÎŒ\mum; inner ∌\sim50 pc) in a sample of local AGN with different levels of nuclear obscuration in the range log NHX−Ray_{\rm H}^{\rm X-Ray}(cm−2^{-2})∌22−25\sim22-25. We find a good correlation between the 6 ÎŒ\mum water ice optical depths and NHX−Ray_{\rm H}^{\rm X-Ray}. This result indicates that the water ice absorption might be a reliable tracer of the nuclear intrinsic obscuration in AGN. The weak water ice absorption in less obscured AGN (log NHX−ray_H^{X-ray} (cm−2^{-2})â‰Č\lesssim23.0 cm−2^{-2}) might be related to the hotter dust temperature (>>TsubH2O∌_{sub}^{H_2O}\sim110 K) expected to be reached in the outer layers of the torus due to their more inhomogeneous medium. Our results suggest it might be necessary to include the molecular content, such as, H2_2O, aliphatic hydrocarbons (CH-) and more complex PAH molecules in torus models to better constrain key parameters such as the torus covering factor (i.e. nuclear obscuration).Comment: Accepted for publication in A&A. 13 pages, 12 Figure

    Influence of the length of hospitalisation in post-discharge outcomes in patients with acute heart failure: Results of the LOHRCA study

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    Objective: To investigate the relationship between length of hospitalisation (LOH) and post-discharge outcomes in acute heart failure (AHF) patients and to ascertain whether there are different patterns according to department of initial hospitalisation. Methods: Consecutive AHF patients hospitalised in 41 Spanish centres were grouped based on the LOH (15 days). Outcomes were defined as 90-day post-discharge all-cause mortality, AHF readmissions, and the combination of both. Hazard ratios (HRs), adjusted by chronic conditions and severity of decompensation, were calculated for groups with LOH >6 days vs. LOH <6 days (reference), and stratified by hospitalisation in cardiology, internal medicine, geriatrics, or short-stay units. Results: We included 8563 patients (mean age: 80 (SD = 10) years, 55.5% women), with a median LOH of 7 days (IQR 4–11): 2934 (34.3%) had a LOH 15 days. The 90-day post-discharge mortality was 11.4%, readmission 32.2%, and combined endpoint 37.4%. Mortality was increased by 36.5% (95%CI = 13.0–64.9) when LOH was 11–15 days, and by 72.0% (95%CI = 42.6–107.5) when >15 days. Conversely, no differences were found in readmission risk, and the combined endpoint only increased 21.6% (95%CI = 8.4–36.4) for LOH >15 days. Stratified analysis by hospitalisation departments rendered similar post-discharge outcomes, with all exhibiting increased mortality for LOH >15 days and no significant increments in readmission risk. Conclusions: Short hospitalisations are not associated with worse outcomes. While post-discharge readmissions are not affected by LOH, mortality risk increases as the LOH lengthens. These findings were similar across hospitalisation departments
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