Suchergebnisse

We identify stellar structures in the PHANGS sample of 74 nearby galaxies and construct morphological masks of sub-galactic environments based on Spitzer 3.6 mu m images. At the simplest level, we distinguish five environments: centres, bars, spiral arms, interarm regions, and discs without strong spirals. Slightly more sophisticated masks include rings and lenses, which are publicly released but not explicitly used in this paper. We examine trends with environment in the molecular gas content, star formation rate, and depletion time using PHANGS-ALMA CO(2-1) intensity maps and tracers of star formation. The interarm regions and discs without strong spirals clearly dominate in area, whereas molecular gas and star formation are quite evenly distributed among the five basic environments. We reproduce the molecular Kennicutt-Schmidt relation with a slope compatible with unity within the uncertainties and without significant slope differences among environments. In contrast to what has been suggested by early studies, we find that bars are not always deserts devoid of gas and star formation, but instead they show large diversity. Similarly, spiral arms do not account for most of the gas and star formation in disc galaxies, and they do not have shorter depletion times than the interarm regions. Spiral arms accumulate gas and star formation, without systematically boosting the star formation efficiency. Centres harbour remarkably high surface densities and on average shorter depletion times than other environments. Centres of barred galaxies show higher surface densities and wider distributions compared to the outer disc; yet, depletion times are similar to unbarred galaxies, suggesting highly intermittent periods of star formation when bars episodically drive gas inflow, without enhancing the central star formation efficiency permanently. In conclusion, we provide quantitative evidence that stellar structures in galaxies strongly affect the organisation of molecular gas and star formation, but their impact on star formation efficiency is more subtle. ; Instituto de Salud Carlos III Spanish Government PID2019-106027GA-C44 European Research Council (ERC) 694343 National Science Foundation (NSF) National Research Foundation of Korea 1615105 1615109 1653300 National Aeronautics and Space Administration (NASA) under ADAP grants NNX16AF48G NNX17AF39G German Research Foundation (DFG) SFB 881 138713538 Heidelberg Cluster of Excellence "STRUCTURES" in the framework of Germany's Excellence Strategy EXC-2181/1 390900948 European Research Council via the ERC Synergy Grant "ECOGAL" 855130 SKA South Africa 694343 721463 726384/Empire Academy of Finland 297738 German Research Foundation (DFG) KR4801/1-1 KR4598/2-1 KR4801/2-1 BI1546/3-1 European Research Council (ERC) 714907 National Science Foundation (NSF) 1903946 Spanish Government AYA2016-79006-P Spanish Government European Commission PID2019-108765GB-I00 Programme National Cosmology et Galaxies (PNCG) of CNRS/INSU INP IN2P3 French Atomic Energy Commission Centre National D'etudes Spatiales Programme National 'Physique et Chimie du Milieu Interstellaire' (PCMI) of CNRS/INSU INC/INP - CEA Natural Sciences and Engineering Research Council of Canada (NSERC) RGPIN-2017-03987 Spanish funding grant (MINECO/FEDER) AYA2016-79006-P Spanish funding grant (MCIU/AEI/FEDER) PGC2018-094671-B-I00 Spanish funding grant (MICINN) PID2019-108765GB-I00 German Research Foundation (DFG) 138713538 - SFB 881 ; Versión sometida a revisión - Preprint

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2012 RAS © 2012 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. ; In this work we present a detailed analysis of the global and fine structure of four middlemass disc galaxies obtained from hydrodynamic simulations in a cold dark matter ( CDM) scenario. These objects have photometric disc-to-total ratios in good agreement with those observed for late-type spirals, as well as kinematic properties in agreement with the observational I-band Tully–Fisher relation.We identify the different dynamical components at redshift zero on the basis of both orbital parameters and the binding energy of stars in the galaxy. In this way, we recognize a slowly rotating centrally concentrated spheroid, and two disc components supported by rotation: a thin discwith stars in nearly circular orbits, and a thick disc with orbital parameters transitional between the thin disc and the spheroid. The spheroidal component is composed mainly by old, metal-poor and α-enhanced stars. The distribution of metals in this component shows, however, a clear bimodality with a low-metallicity peak, which could be related to a classical bulge formed from rapid collapse at early times, and a high-metallicity peak, which could be related to a pseudo-bulge formed from instabilities of the inner disc. The thin disc appears in our simulations as the youngest and most metal-rich component, with median stellar ages ranging from 3.8 to 6.7 Gyr. The radial distribution of ages and colours in this component is U-shaped: the new stars are forming in the inner regions, where the galaxy is bluer, and then migrate through secular processes reaching the outer parts. Finally, we also find in all simulated galaxies a thick disc containing about 16 per cent of the total stellar mass and with properties that are intermediate between those of the thin disc and the spheroid. Its low-metallicity stars are α-enhanced when compared to thin disc stars of the same metallicity. The structural parameters (e.g. the scale height) of the simulated thick discs suggest that such a component could result from the combination of different thickening mechanisms that include merger-driven processes, but also long-lived internal perturbations of the thin disc. ; This work was partially supported by the DGES (Spain) through the grants AYA2009-12792-C03-02 and AYA2009-12792- C03-03 from the PNAyA, MICINN, Spain. We also thank the ASTROMADRID network (CAM S2009/ESP-1496) from the Madrid regional government, and the 'Supercomputación y e-Ciencia' Consolider-Ingenio 2010 project (CSD2007-0050), MICINN, Spain.

Based on observations made with the JAST/T80 telescope for J-PLUS project at the Observatorio Astrofisico de Javalambre in Teruel, a Spanish Infraestructura Cientifico-Tecnica Singular (ICTS) owned, managed and operated by the Centro de Estudios de Fisica del Cosmos de Aragon (CEFCA). Data has been processed and provided by CEFCA's Unit of Processing and Archiving Data (UPAD). Funding for the J-PLUS Project has been provided by the Governments of Spain and Aragon through the Fondo de Inversiones de Teruel; the Aragon Government through the Research Groups E96, E103, and E16_17R; the Spanish Ministry of Science, Innovation and Universities (MCIU/AEI/FEDER, UE) with grants PGC2018-097585-B-C21 and PGC2018-097585-B-C22; the Spanish Ministry of Economy and Competitiveness (MINECO) under AYA2015-66211-C2-1-P, AYA2015-66211-C2-2, AYA2012-30789, and ICTS-2009-14; and European FEDER funding (FCDD104E-867, FCDD13-4E-2685). The Brazilian agencies FINEP, FAPESP, and the National Observatory of Brazil have also contributed to this project. We thank the comments and suggestions of the referee, that improved the manuscript and the quality of the results. G.V.R. wants to thank A. and K. Gavin O'Shaughnessy for the language corrections. J.M.V. acknowledges financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV2017-0709), and grant AYA2016-79724-C4-4P. R.A.D. acknowledges support from the Conselho Nacional de Desenvolvimento Cientifico e Tecnolagico CNPq through BP grant 308105/2018-4, and the Financiadora de Estudos e Projetos -FINEP grants REF. 1217/13 -01.13.0279.00 and REF 0859/10 -01.10.0663.00 for hardware support for the J-PLUS project through the National Observatory of Brazil. We thank the help of Prof. G. Gavazzi in the analysis and understanding of Hff3 data. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research made use of Astropy, a community-developed core Python package for Astronomy (Astropy Collaboration 2013), and Matplotlib, a 2D graphics package used for Python for publication-quality image generation across user interfaces and operating systems (Hunter 2007). Some of the data sets discussed in the manuscript were recovered with WebPlotDigitizer (https://automeris.io/WebPlotDigitizer/index.html), a free software developed to facilitate easy and accurate data extraction from a variety of plot types. ; Aims. Our goal is to estimate the star formation main sequence (SFMS) and the star formation rate density (SFRD) at z <= 0.017 (d less than or similar to 75 Mpc) using the Javalambre Photometric Local Universe Survey (J-PLUS) first data release, that probes 897.4 deg(2) with twelve optical bands.Methods. We extract the H alpha emission flux of 805 local galaxies from the J-PLUS filter J0660, being the continuum level estimated with the other eleven J-PLUS bands, and the dust attenuation and nitrogen contamination corrected with empirical relations. Stellar masses (M-star), H alpha luminosities (L-H alpha), and star formation rates (SFRs) were estimated by accounting for parameters covariances. Our sample comprises 689 blue galaxies and 67 red galaxies, classified in the (u-g) vs. (g-z) color-color diagram, plus 49 AGN.Results. The SFMS is explored at log M-star greater than or similar to 8 and it is clearly defined by the blue galaxies, with the red galaxies located below them. The SFMS is described as log SFR=0.83log M-star-8.44. We find a good agreement with previous estimations of the SFMS, especially those based on integral field spectroscopy. The H alpha luminosity function of the AGN-free sample is well described by a Schechter function with log L-H alpha = 41.34 log L H alpha = 41.34 , log (*)=-2.43, and alpha=-1.25. Our measurements provide a lower characteristic luminosity than several previous studies in the literature.Conclusions. The derived star formation rate density at d less than or similar to 75 Mpc is log rho (SFR)=-2.10 +/- 0.11, with red galaxies accounting for 15% of the SFRD. Our value is lower than previous estimations at similar redshift, and provides a local reference for evolutionary studies regarding the star formation history of the Universe. ; Government of Spain through the Fondo de Inversiones de Teruel ; Government of Aragon through the Fondo de Inversiones de Teruel ; Spanish Ministry of Science, Innovation and Universities (MCIU/AEI/FEDER, UE) PGC2018-097585-B-C21 PGC2018-097585-B-C22 ; Spanish Ministry of Economy and Competitiveness (MINECO) AYA2015-66211-C2-1-P AYA2015-66211-C2-2 AYA2012-30789 ICTS-2009-14 ; European FEDER funding FCDD104E-867 FCDD13-4E-2685 ; State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award SEV2017-0709 AYA2016-79724-C4-4P ; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) ; Fundacao de Apoio a Pesquisa do Distrito Federal (FAPDF) 308105/2018-4 ; Financiadora de Estudos e Projetos -FINEP through the National Observatory of Brazil REF. 1217/13 -01.13.0279.00 REF 0859/10 -01.10.0663.00 ; National Aeronautics & Space Administration (NASA) ; Aragon Government through the Research Group E96 Aragon Government through the Research Group E103 Aragon Government through the Research Group E16_17R

We thanks CONACYT FC-2016-01-1916 and CB-285080 projects and PAPIIT IN100519 project for support on this study. LG was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 839090. EADLthanks all Stellar Population Synthesis and Chemical Evolution group of the Instituto de Astronomia-UNAM for the help through the by-eye morphological classification. ; We study the presence of optically-selected active galactic nuclei (AGNs) within a sample of 867 galaxies extracted from the extended Calar-Alto Legacy Integral Field spectroscopy Area (eCALIFA) spanning all morphological classes. We identify 10 Type-I and 24 Type-II AGNs, amounting to ∼4 per cent of our sample, similar to the fraction reported by previous explorations in the same redshift range. We compare the integrated properties of the ionized and molecular gas, and stellar population of AGN hosts and their non-active counterparts, combining them with morphological information. The AGN hosts are found in transitory parts (i.e. green-valley) in almost all analysed properties which present bimodal distributions (i.e. a region where reside star-forming galaxies and another with quiescent/retired ones). Regarding morphology, we find AGN hosts among the most massive galaxies, with enhanced central stellar-mass surface density in comparison to the average population at each morphological type. Moreover, their distribution peaks at the Sab-Sb classes and none are found among very late-type galaxies (>Scd). Finally, we inspect how the AGN could act in their hosts regarding the quenching of star-formation. The main role of the AGN in the quenching process appears to be the removal (or heating) of molecular gas, rather than an additional suppression of the already observed decrease of the star-formation efficiency from late-to-early type galaxies. ; Consejo Nacional de Ciencia y Tecnologia (CONACyT) FC-2016-01-1916 CB-285080 ; European Commission 839090 ; Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT) IN100519

We thank the anonymous referee for a constructive and detailed report. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska Curie grant agreement No 893673. We acknowledge financial support from the European Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement No 721463 to the SUNDIAL ITN network, from the State Research Agency (AEI-MCINN) of the Spanish Ministry of Science and Innovation under the grant "The structure and evolution of galaxies and their central regions" with reference PID2019-105602GBI00/10.13039/501100011033, and from IAC project P/300724, financed by the Ministry of Science and Innovation, through the State Budget and by the Canary Islands Department of Economy, Knowledge and Employment, through the Regional Budget of the Autonomous Community. SDG acknowledges support from the Spanish Public Employment Service (SEPE). Furthermore, we acknowledge support by the research project AYA2017-84897-P from the Spanish Ministerio de Economia y Competitividad, from the European Regional Development Funds (FEDER) and the Junta de Andalucia (Spain) grants FQM108. DE acknowledges support from a Beatriz Galindo senior fellowship (BG20/00224) from the Ministry of Science and Innovation. LVM acknowledges financial support from the grants AYA2015-65973-C3-1-R and RTI2018096228-B-C31 (MINECO/FEDER, UE), as well as from the State Agency for Research of the Spanish MCIU through the Center of Excellence Severo Ochoa award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709). This research makes use of python (http://www.python.org), Matplotlib (Hunter 2007), and Astropy (Astropy Collaboration 2013, 2018). We acknowledge the usage of the HyperLeda database (http://leda.univ-lyon1.fr).We thank Alexandre Bouquin for providing us with the GALEX FUV and NUV images used in this work. We thank Stephane Courteau, Estrella Florido, Raul Infante-Sainz, Tom Jarrett, Johan H. Knapen, Heikki Salo, and Miguel Querejeta for useful discussions. We thank Sebastien Comeron and Facundo D. Moyano for valuable comments on the manuscript. Facilities: GALEX, WISE, Spitzer (IRAC). ; Context. While some galactic bars show recent massive star formation (SF) along them, some others do not. Whether bars with low level of SF are a consequence of low star formation efficiency, low gas inflow rate, or dynamical effects remains a matter of debate. Aims. In order to study the physical conditions that enable or prevent SF, we perform a multi-wavelength analysis of 12 strongly barred galaxies with total stellar masses log(10)(M-*/M-circle dot)is an element of[10.2,11], chosen to host different degrees of SF along the bar major axis without any prior condition on gas content. We observe the CO(1-0) and CO(2-1) emission within bars with the IRAM-30 m telescope (beam sizes of 1.7-3.9 kpc and 0.9-2.0 kpc, respectively; 7-8 pointings per galaxy on average). Methods. We estimated molecular gas masses (M-mol) from the CO(1-0) and CO(2-1) emissions. SF rates (SFRs) were calculated from GALEX near-ultraviolet (UV) and WISE 12 mu m images within the beam-pointings, covering the full bar extent (SFRs were also derived from far-UV and 22 mu m). Results. We detect molecular gas along the bars of all probed galaxies. Molecular gas and SFR surface densities span the ranges log(10)(sigma(mol)/[M-circle dot pc(-2)]) is an element of [0.4,2.4] and log(10)(sigma(SFR)/[M-circle dot pc(-1) kpc(-2)]]) is an element of [-3.25, -0.75], respectively. The star formation efficiency (SFE; i.e., SFR/M-mol) in bars varies between galaxies by up to an order of magnitude (SFE is an element of[0.1,1.8] Gyr(-1)). On average, SFEs are roughly constant along bars. SFEs are not significantly different from the mean value in spiral galaxies reported in the literature (similar to 0.43 Gyr(-1)), regardless of whether we estimate M-mol from CO(1-0) or CO(2-1). Interestingly, the higher the total stellar mass of the host galaxy, the lower the SFE within their bars. In particular, the two galaxies in our sample with the lowest SFE and sigma(SFR) (NGC 4548 and NGC 5850, SFE less than or similar to 0.25 Gyr(-1), sigma(SFR)less than or similar to 10(-2.25)M(circle dot) yr(-1) kpc(-2), M greater than or similar to 10(10.7)M(circle dot)) are also those hosting massive bulges and signs of past interactions with nearby companions. Conclusions. We present a statistical analysis of the SFE in bars for a sample of 12 galaxies. The SFE in strong bars is not systematically inhibited (either in the central, middle, or end parts of the bar). Both environmental and internal quenching are likely responsible for the lowest SFEs reported in this work. ; European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska Curie 893673 ; European Commission 721463 ; State Research Agency (AEI-MCINN) of the Spanish Ministry of Science and Innovation under the grant "The structure and evolution of galaxies and their central regions" - Ministry of Science and Innovation P/300724 PID2019-105602GBI00 ; Spanish Public Employment Service (SEPE) ; Spanish Ministerio de Economia y Competitividad, from the European Regional Development Funds (FEDER) AYA2017-84897-P ; Junta de Andalucia ; European Commission FQM108 ; Spanish Government BG20/00224 ; State Agency for Research of the Spanish MCIU through the Center of Excellence Severo Ochoa award SEV-2017-0709 ; Canary Islands Department of Economy, Knowledge and Employment, through the Regional Budget of the Autonomous Community ; MINECO/FEDER, UE AYA2015-65973-C3-1-R RTI2018096228-B-C31

Context. While some galactic bars show recent massive star formation (SF) along them, some others do not. Whether bars with low level of SF are a consequence of low star formation efficiency, low gas inflow rate, or dynamical effects remains a matter of debate. Aims. In order to study the physical conditions that enable or prevent SF, we perform a multi-wavelength analysis of 12 strongly barred galaxies with total stellar masses log10(M⊙/M⊙)? [10.2, 11], chosen to host different degrees of SF along the bar major axis without any prior condition on gas content. We observe the CO(1-0) and CO(2-1) emission within bars with the IRAM-30 m telescope (beam sizes of 1.7-3.9 kpc and 0.9-2.0 kpc, respectively; 7-8 pointings per galaxy on average). Methods. We estimated molecular gas masses (Mmol) from the CO(1-0) and CO(2-1) emissions. SF rates (SFRs) were calculated from GALEX near-ultraviolet (UV) and WISE 12 μm images within the beam-pointings, covering the full bar extent (SFRs were also derived from far-UV and 22 μm). Results. We detect molecular gas along the bars of all probed galaxies. Molecular gas and SFR surface densities span the ranges log10(ςmol/[M⊙ pc-2]) ? [0.4,2.4] and log10(ςSFR/[M⊙ pc-1 kpc-2]]) ? [-3.25, -0.75], respectively. The star formation efficiency (SFE; i.e., SFR/Mmol) in bars varies between galaxies by up to an order of magnitude (SFE ? [0.1, 1.8] Gyr-1). On average, SFEs are roughly constant along bars. SFEs are not significantly different from the mean value in spiral galaxies reported in the literature (∼0.43 Gyr-1), regardless of whether we estimate Mmol from CO(1-0) or CO(2-1). Interestingly, the higher the total stellar mass of the host galaxy, the lower the SFE within their bars. In particular, the two galaxies in our sample with the lowest SFE and ςSFR (NGC 4548 and NGC 5850, SFE ? 0.25 Gyr-1, ςSFR ? 10-2.25 M⊙ yr-1 kpc-2, M⊙ ? 1010.7 M⊙) are also those hosting massive bulges and signs of past interactions with nearby companions. Conclusions. We present a statistical analysis of the SFE in bars for a sample of 12 galaxies. The SFE in strong bars is not systematically inhibited (either in the central, middle, or end parts of the bar). Both environmental and internal quenching are likely responsible for the lowest SFEs reported in this work. © ESO 2021. ; This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska Curie grant agreement No 893673. We acknowledge financial support from the European Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement No 721463 to the SUNDIAL ITN network, from the State Research Agency (AEI-MCINN) of the Spanish Ministry of Science and Innovation under the grant "The structure and evolution of galaxies and their central regions" with reference PID2019-105602GB-I00/10.13039/501100011033, and from IAC project P/300724, financed by the Ministry of Science and Innovation, through the State Budget and by the Canary Islands Department of Economy, Knowledge and Employment, through the Regional Budget of the Autonomous Community. SDG acknowledges support from the Spanish Public Employment Service (SEPE). Furthermore, we acknowledge support by the research project AYA2017-84897-P from the Spanish Ministerio de Economia y Competitividad, from the European Regional Development Funds (FEDER) and the Junta de Andalucia (Spain) grants FQM108. DE acknowledges support from a Beatriz Galindo senior fellowship (BG20/00224) from the Ministry of Science and Innovation. LVM acknowledges financial support from the grants AYA2015-65973-C3-1-R and RTI2018-096228-B-C31 (MINECO/FEDER, UE), as well as from the State Agency for Research of the Spanish MCIU through the Center of Excellence Severo Ochoa award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709). This research makes use of python (http://www.python.org), Matplotlib (Hunter 2007), and Astropy (Astropy Collaboration 2013, 2018). We acknowledge the usage of the HyperLeda database (http://leda.univ-lyon1.fr). ; Peer reviewed

We present a pilot search of CO emission in three H2-absorbing, long-duration gamma-ray burst (GRB) host galaxies at z ∼ 2-3. We used the Atacama Large Millimeter/submillimeter Array (ALMA) to target the CO(3 - 2) emission line and report nondetections for all three hosts. These are used to place limits on the host molecular gas masses, assuming a metallicity-dependent CO-to-H2 conversion factor (αCO). We find, Mmol < 3.5 × 1010M⊙ (GRB 080607), Mmol < 4.7 × 1011M⊙ (GRB 120815A), and Mmol [removed]1 with M∗ < 1010M⊙. To better quantify this we develop a simple approach to estimate the relevant αCO factor based only on the redshift and stellar mass of individual galaxies. The elevated conversion factors will make these galaxies appear CO-'dark' and difficult to detect in emission, as is the case for the majority of GRB hosts. GRB spectroscopy thus offers a complementary approach to identify low-metallicity, star-forming galaxies with abundant molecular gas reservoirs at high redshifts that are otherwise missed by current ALMA surveys. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. ; KEH and PJ acknowledge support by a Project Grant (162948-051) from The Icelandic Research Fund. MN acknowledges support from ERC Advanced grant 740246 (Cosmic Gas). JPUF thanks the Carlsberg Foundation for support. The Cosmic DAWN Center is funded by the DNRF. PN and JKK acknowledge support from the French Agence Nationale de la Recherche under grant ANR 17-CE31-001101/project `HIH2' (PI: Noterdaeme). This paper makes use of the following ALMA data: ADS/JAO.ALMA#2019.1.00407.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST 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. ; With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709. ; Peer reviewed

Aims. The complexity of star formation at the physical scale of molecular clouds is not yet fully understood. We investigate the mechanisms regulating the formation of stars in di erent environments within nearby star-forming galaxies from the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) sample. Methods. Integral field spectroscopic data and radio-interferometric observations of 18 galaxies were combined to explore the existence of the resolved star formation main sequence ( stellar versus SFR), resolved Kennicutt–Schmidt relation ( mol: gas versus SFR), and resolved molecular gas main sequence ( stellar versus mol: gas), and we derived their slope and scatter at spatial resolutions from 100 pc to 1 kpc (under various assumptions). Results. All three relations were recovered at the highest spatial resolution (100 pc). Furthermore, significant variations in these scaling relations were observed across di erent galactic environments. The exclusion of non-detections has a systematic impact on the inferred slope as a function of the spatial scale. Finally, the scatter of the mol: gas+stellar versus SFR correlation is smaller than that of the resolved star formation main sequence, but higher than that found for the resolved Kennicutt–Schmidt relation. Conclusions. The resolved molecular gas main sequence has the tightest relation at a spatial scale of 100 pc (scatter of 0:34 dex), followed by the resolved Kennicutt–Schmidt relation (0:41 dex) and then the resolved star formation main sequence (0:51 dex). This is consistent with expectations from the timescales involved in the evolutionary cycle of molecular clouds. Surprisingly, the resolved Kennicutt–Schmidt relation shows the least variation across galaxies and environments, suggesting a tight link between molecular gas and subsequent star formation. The scatter of the three relations decreases at lower spatial resolutions, with the resolved Kennicutt–Schmidt relation being the tightest (0:27 dex) at a spatial scale of 1 kpc. Variation in the slope of the resolved star formation main sequence among galaxies is partially due to di erent detection fractions of SFR with respect to stellar. ; European Research Council (ERC) 694343 726384/Empire National Science Foundation (NSF) 1615105 1615109 1653300 ANID project Basal AFB-170002 German Research Foundation (DFG) KR4801/1-1 German Research Foundation (DFG) European Commission KR4801/2-1 SFB 881 138713538 European Research Council (ERC) 714907 German Research Foundation (DFG) KR4598/2-1 Instituto de Salud Carlos III Spanish Government PID2019-106027GA-C44 Spanish funding grant (MINECO/FEDER) AYA2016-79006-P Spanish funding grant (MCIU/AEI/FEDER) PGC2018-094671-B-I00 Spanish funding grant (MICINN) PID2019-108765GB-I00 European Research Council (ERC) European Commission 855130 Heidelberg cluster of excellence - German Excellence Strategy EXC 2181 - 390900948 European Organisation for Astronomical Research in the Southern Hemisphere under ESO 094.C-0623 098.C-0484 1100.B-0651 ; Versión publicada - versión final del editor

36 pages, 18 figures, 4 tables, 1 appendix.-- Pre-print archive. ; We show that measures of star formation rates (SFRs) for infrared galaxies using either single-band 24 um or extinction-corrected Paschen-alpha luminosities are consistent in the total infrared luminosity = L(TIR) ~ 10^10 L_sun range. MIPS 24 micron photometry can yield star formation rates accurately from this luminosity upward: SFR(M_sun/yr) = 7.8 x 10^-10 L(24 um, L_sun) from L(TIR) = 5 x 10^9 L_sun to 10^11 L_sun, and SFR = 7.8 x 10^-10 L(24 um, L_sun) x (7.76 x 10^-11 L(24))^0.048 for higher L(TIR). For galaxies with L(TIR) >= 10^10 L_sun, these new expressions should provide SFRs to within 0.2 dex. For L(TIR) >= 10^11 L_sun, we find that the SFR of infrared galaxies is significantly underestimated using extinction-corrected Pa-alpha (and presumably using any other optical or near infrared recombination lines). As a part of this work, we constructed spectral energy distribution (SED) templates for eleven luminous and ultraluminous purely star forming infrared galaxies (LIRGs and ULIRGs) and over the spectral range 0.4 microns to 30 cm. We use these templates and the SINGS data to construct average templates from 5 microns to 30 cm for infrared galaxies with L(TIR) = 5 x 10^9 to 10^13 L_sun. All of these templates are made available on line. ; Support for this work was provided by NASA through JPL/Caltech contract 1255094 and by NAG5-12318 from NASA/Goddard to the University of Arizona. Funding for the DEEP2 survey has been provided by NSF grants AST95-09298, AST-0071048, AST-0071198, AST-0507428, and AST- 0507483 as well as NASA LTSA grant NNG04GC89G. P. G. Pérez-González acknowledges support from the grants PNAYA 2006–02358 and PNAYA 2006–15698– C02–02 and from the Ramón y Cajal Program, financed by the Spanish Government and the European Union. ; Peer reviewed

We report ALMA observations with resolution approximate to 0 ''.5 at 3 mm of the extended Sgr B2 cloud in the Central Molecular Zone (CMZ). We detect 271 compact sources, most of which are smaller than 5000 au. By ruling out alternative possibilities, we conclude that these sources consist of a mix of hypercompact H II regions and young stellar objects (YSOs). Most of the newly detected sources are YSOs with gas envelopes that, based on their luminosities, must contain objects with stellar masses M* greater than or similar to 8M(circle dot). Their spatial distribution spread over a similar to 12 x 3 pc region demonstrates that Sgr B2 is experiencing an extended star formation event, not just an isolated "starburst" within the protocluster regions. Using this new sample, we examine star formation thresholds and surface density relations in Sgr B2. While all of the YSOs reside in regions of high column density (N(H-2) greater than or similar to 2 x 10(23) cm(-2) not all regions of high column density contain YSOs. The observed column density threshold for star formation is substantially higher than that in solar vicinity clouds, implying either that high-mass star formation requires a higher column density or that any star formation threshold in the CMZ must be higher than in nearby clouds. The relation between the surface density of gas and stars is incompatible with extrapolations from local clouds, and instead stellar densities in Sgr B2 follow a linear Sigma(*)-Sigma(gas) relation, shallower than that observed in local clouds. Together, these points suggest that a higher volume density threshold is required to explain star formation in CMZ clouds. ; National Science Foundation AST-1615311 German Research Foundation (DFG) KR4801/1-1 European Research Council (ERC) under the European Union's Horizon research and innovation program via the ERC Starting Grant MUSTANG 714907 DFG Sonderforschungsbereich SFB 881 UNAM-PAPIIT program IA102817 NSF through the Grote Reber Fellowship Program Deutsche Forschungsgemeinschaft SFB956 European Research Council (ERC) PALs 320620

Aims. Our goal is to estimate the star formation main sequence (SFMS) and the star formation rate density (SFRD) at z = 0.017 (d . 75 Mpc) using the Javalambre Photometric Local Universe Survey (J-PLUS) first data release, that probes 897.4 deg2 with twelve optical bands. Methods. We extract the Ha emission flux of 805 local galaxies from the J-PLUS filter J0660, being the continuum level estimated with the other eleven J-PLUS bands, and the dust attenuation and nitrogen contamination corrected with empirical relations. Stellar masses (M), Ha luminosities (LHa), and star formation rates (SFRs) were estimated by accounting for parameters covariances. Our sample comprises 689 blue galaxies and 67 red galaxies, classified in the (u - g) vs. (g - z) color–color diagram, plus 49 AGN. Results. The SFMS is explored at log M 8 and it is clearly defined by the blue galaxies, with the red galaxies located below them. The SFMS is described as log SFR = 0.83 log M -8.44. We find a good agreement with previous estimations of the SFMS, especially those based on integral field spectroscopy. The Ha luminosity function of the AGN-free sample is well described by a Schechter function with log L * Ha = 41.34, log f * = -2.43, and a = -1.25. Our measurements provide a lower characteristic luminosity than several previous studies in the literature. Conclusions. The derived star formation rate density at d . 75 Mpc is log SFR = -2.10 ± 0.11, with red galaxies accounting for 15% of the SFRD. Our value is lower than previous estimations at similar redshift, and provides a local reference for evolutionary studies regarding the star formation history of the Universe © 2021 EDP Sciences. All rights reserved. ; Based on observations made with the JAST/T80 telescope for J-PLUS project at the Observatorio Astrofísico de Javalambre in Teruel, a Spanish Infraestructura Cientifico-Técnica Singular (ICTS) owned, managed and operated by the Centro de Estudios de Física del Cosmos de Aragón (CEFCA). Data has been processed and provided by CEFCA's Unit of Processing and Archiving Data (UPAD). Funding for the J-PLUS Project has been provided by the Governments of Spain and Aragón through the Fondo de Inversiones de Teruel; the Aragón Government through the Research Groups E96, E103, and E16_17R; the Spanish Ministry of Science, Innovation and Universities (MCIU/AEI/FEDER, UE) with grants PGC2018-097585-B-C21 and PGC2018-097585-B-C22; the Spanish Ministry of Economy and Competitiveness (MINECO) under AYA2015-66211-C2-1-P, AYA2015-66211-C2-2, AYA2012-30789, and ICTS-2009-14; and European FEDER funding (FCDD10- 4E-867, FCDD13-4E-2685). The Brazilian agencies FINEP, FAPESP, and the National Observatory of Brazil have also contributed to this project. J.M.V. acknowledges financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofísica de Andalucía (SEV 2017-0709), and grant AYA2016-79724-C4-4P. R.A.D. acknowledges support from the Conselho Nacional de Desenvolvimento Científico e Tecnolágico –CNPq through BP grant 308105/2018-4, and the Financiadora de Estudos e Projetos – FINEP grants REF. 1217/13 – 01.13.0279.00 and REF 0859/10 – 01.10.0663.00 for hardware support for the J-PLUS project through the National Observatory of Brazil. We thank the help of Prof. G. Gavazzi in the analysis and understanding of Hα3 data. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research made use of Astropy, a community-developed core Python package for Astron omy (Astropy Collaboration 2013), and Matplotlib, a 2D graphics package used for Python for publication-quality image generation across user interfaces and operating systems (Hunter 2007). Some of the data sets discussed in the manuscript were recovered with WebPlotDigitizer (https://automeris.io/WebPlotDigitizer/index.html), a free software developed to facilitate easy and accurate data extraction from a variety of plot types. ; Peer reviewed

Using the Very Large Array (VLA), we recently detected a large number of protoplanetary disc (proplyd) candidates lying within a couple of light years of the massive black hole Sgr A*. The bow-shock appearance of proplyd candidates points towards the young massive stars located near Sgr A*. Similar to Orion proplyds, the strong UV radiation from the cluster of massive stars at the Galactic centre is expected to photoevaporate and photoionize the circumstellar discs around young, low-mass stars, thus allowing detection of the ionized outflows from the photoionized layer surrounding cool and dense gaseous discs. To confirm this picture, ALMA observations detect millimeter emission at 226 GHz from five proplyd candidates that had been detected at 44 and 34 GHz with the VLA. We present the derived disc masses for four sources as a function of the assumed dust temperature. The mass of protoplanetary discs from cool dust emission ranges between 0.03 and 0.05 M-circle dot. These estimates are consistent with the disc masses found in star-forming sites in the Galaxy. These measurements show the presence of ongoing star formation with the implication that gas clouds can survive near Sgr A* and the relative importance of high-versus low-mass star formation in the strong tidal and radiation fields of the Galactic centre. ; This work is partially supported by the grant AST-1517246 from the NSF. RS acknowledges funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement [614922]. ; Peer reviewed