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Measurement of Spin-density Matrix Elements in ∆++(1232) photoproduction

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arXiv 2024年

作者： Afzal, F. Akondi, C.S. Albrecht, M. Amaryan, M. Arrigo, S. Arroyave, V. Asaturyan, A. Austregesilo, A. Baldwin, Z. Barbosa, F. Barlow, J. Barriga, E. Barsotti, R. Barton, d. Baturin, V. Berdnikov, V.V. Black, T. Boeglin, W. Boer, M. Briscoe, W.J. Britton, T. Cao, S. Chudakov, E. Chung, G. Cole, P.l. Cortes, O. Crede, V. dalton, M.M. darulis, d. deur, A. dobbs, S. dolgolenko, A. dugger, M. dzhygadlo, R. Ebersole, d. Edo, M. Egiyan, H. Erbora, T. Eugenio, P. Fabrizi, A. Fanelli, C. Fang, S. Fitches, J. Foda, A.M. Furletov, S. Gan, l. Gao, H. Gardner, A. Gasparian, A. Glazier, d.I. Gleason, C. Goryachev, V.S. Grube, B. Guo, J. Guo, l. Hernandez, J. Hernandez, K. Hoffman, N.d. Hornidge, d. Hou, G. Hurck, P. Hurley, A. Imoehl, W. Ireland, d.G. Ito, M.M. Jaegle, I. Jarvis, N.S. Jeske, T. Jing, M. Jones, R.T. Kakoyan, V. Kalicy, G. Khachatryan, V. Kourkoumelis, C. laduke, A. larin, I. lawrence, d. lersch, d.I. li, H. liu, B. livingston, K. lolos, G.J. lorenti, l. lyubovitskij, V. Ma, R. Mack, d. Mahmood, A. Marukyan, H. Matveev, V. McCaughan, M. McCracken, M. Meyer, C.A. Miskimen, R. Mitchell, R.E. Mizutani, K. Neelamana, V. Ng, l. Nissen, E. Orešić, S. Ostrovidov, A.I. Papandreou, Z. Paudel, C. Pedroni, R. Pentchev, l. Peters, K.J. Prather, E. Rakshit, S. Reinhold, J. Remington, A. Ritchie, B.G. Ritman, J. Rodriguez, G. Romanov, d. Saldana, K. Salgado, C. Schadmand, S. Schertz, A.M. Scheuer, K. Schick, A. Schmidt, A. Schumacher, R.A. Schwiening, J. Septian, N. Sharp, P. Shen, X. Shepherd, M.R. Sikes, J. Smith, A. Smith, E.S. Sober, d.I. Somov, A. Somov, S. Stevens, J.R. Strakovsky, I.I. Sumner, B. Suresh, K. Tarasov, V.V. Taylor, S. Teymurazyan, A. Thiel, A. Viducic, T. Whitlatch, T. Wickramaarachchi, N. Wunderlich, Y. Yu, B. Zarling, J. Zhang, Z. Zhou, X. Zihlmann, B. Polytechnic Sciences and Mathematics School of Applied Sciences and Arts Arizona State University TempeAZ85287 United States Department of Physics National and Kapodistrian University of Athens Athens15771 Greece Ruhr-Universität-Bochum Institut für Experimentalphysik BochumD-44801 Germany Helmholtz-Institut für Strahlen- und Kernphysik Universität Bonn BonnD-53115 Germany Department of Physics Carnegie Mellon University PittsburghPA15213 United States Department of Physics The Catholic University of America WashingtonDC20064 United States Department of Physics University of Connecticut StorrsCT06269 United States Department of Physics Duke University DurhamNC27708 United States Department of Physics Florida International University MiamiFL33199 United States Department of Physics Florida State University TallahasseeFL32306 United States Department of Physics The George Washington University WashingtonDC20052 United States School of Physics and Astronomy University of Glasgow GlasgowG12 8QQ United Kingdom GSI Helmholtzzentrum für Schwerionenforschung GmbH DarmstadtD-64291 Germany Institute of High Energy Physics Beijing100049 China Department of Physics Indiana University BloomingtonIN47405 United States National Research Centre Kurchatov Institute Moscow123182 Russia Department of Physics Lamar University BeaumontTX77710 United States Department of Physics University of Massachusetts AmherstMA01003 United States National Research Nuclear University Moscow Engineering Physics Institute Moscow115409 Russia Department of Physics Mount Allison University SackvilleNBE4L 1E6 Canada Department of Physics Norfolk State University NorfolkVA23504 United States Department of Physics North Carolina A&T State University GreensboroNC27411 United States Department of Physics and Physical Oceanography University of North Carolina at Wilmington Wilmington28403 United States Department of Physics Old Dominion University Norfo

We measure the spin-density matrix elements (SdMEs) of the ∆++(1232) in the photoproduction reaction γp → π−∆++(1232) with the GlueX experiment in Hall d at Jefferson lab. The measurement uses a linearly-polarized photon beam with energies from 8.2 to 8.8 GeV and the statistical precision of the SdMEs exceeds the previous measurement by three orders of magnitude for the momentum transfer squared region below 1.4 GeV2. The data are sensitive to the previously undetermined relative sign between couplings in existing Regge-exchange models. linear combinations of the extracted SdMEs allow for a decomposition into natural and unnatural-exchange amplitudes. We find that the unnatural exchange plays an important role in the low momentum transfer region. Copyright © 2024, The Authors. All rights reserved.

关键词： Momentum transfer

Quantum technologies for climate change: Preliminary assessment

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arXiv 2021年

作者： Berger, Casey Paolo, Agustin di Forrest, Tracey Hadfield, Stuart Sawaya, Nicolas Stęchly, Michal Thibault, Karl Department of Physics Smith College NorthamptonMA01063 United States Boston University Rafik B Hariri Institute for Computing and Computational Science & Engineering BostonMA02215 United States Département de physique Institut quantique Université de Sherbrooke SherbrookeQCJ1K 2R1 Canada Transformative Quantum Technologies University of Waterloo WaterlooON Canada USRA Research Institute for Advanced Computer Science Mountain ViewCA94043 United States Intel Labs Santa ClaraCA95054 United States Zapata Computing Canada Inc. 325 Front St W TorontoONM5V 2Y1 Canada

Climate change presents an existential threat to human societies and the Earth’s ecosystems more generally. Mitigation strategies naturally require solving a wide range of challenging problems in science, engineering, and economics. In this context, rapidly developing quantum technologies in computing, sensing, and communication could become useful tools to diagnose and help mitigate the effects of climate change. However, the intersection between climate and quantum sciences remains largely unexplored. This preliminary report aims to identify potential high-impact use-cases of quantum technologies for climate change with a focus on four main areas: simulating physical systems, combinatorial optimization, sensing, and energy efficiency. We hope this report provides a useful resource towards connecting the climate and quantum science communities, and to this end we identify relevant research questions and next steps. Copyright © 2021, The Authors. All rights reserved.

关键词： Climate change

Application-Oriented Performance Benchmarks for Quantum Computing

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arXiv 2021年

作者： lubinski, Thomas Johri, Sonika Varosy, Paul Coleman, Jeremiah Zhao, luning Necaise, Jason Baldwin, Charles H. Mayer, Karl Proctor, Timothy Quantum Circuits Inc 25 Science Park New HavenCT06511 United States QED-C Technical Advisory Committee on Standards and Performance Benchmarks United States IonQ Inc 4505 Campus Dr College ParkMD20740 United States Department of Physics Colorado School of Mines GoldenCO80401 United States Department of Electrical and Computer Engineering Princeton University PrincetonNJ08544 United States D-Wave Systems BurnabyBCV5G 4M9 Canada Quantinuum 303 S. Technology Ct BroomfieldCO80021 United States Quantum Performance Laboratory Sandia National Laboratories LivermoreCA94550 United States

In this work we introduce an open source suite of quantum application-oriented performance benchmarks that is designed to measure the effectiveness of quantum computing hardware at executing quantum applications. These benchmarks probe a quantum computer's performance on various algorithms and small applications as the problem size is varied, by mapping out the fidelity of the results as a function of circuit width and depth using the framework of volumetric benchmarking. In addition to estimating the fidelity of results generated by quantum execution, the suite is designed to benchmark certain aspects of the execution pipeline in order to provide end-users with a practical measure of both the quality of and the time to solution. Our methodology is constructed to anticipate advances in quantum computing hardware that are likely to emerge in the next five years. This benchmarking suite is designed to be readily accessible to a broad audience of users and provides benchmarks that correspond to many well-known quantum computing algorithms. Copyright © 2021, The Authors. All rights reserved.

关键词： Benchmarking

IoT Based low-cost Weather Station and Monitoring System for Precision Agriculture in India

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IoT Based Low-cost Weather Station and Monitoring System for...

International Conference on I-SMAC (IoT in Social, Mobile, Analytics and Cloud) (I-SMAC)

作者： Rajinder Kumar M. Math Nagaraj V. dharwadkar Department of ECE B.L.D.E. A’S College of Engineering and Technology Vijayapur Karnataka state India Department of Computer Science and Engineering Rajarambapu Institute of Technology Islampur Maharashtra state India

ISBN: (纸本)9781538614433;9781538614426

In recent times it is seen that the climatic and weather conditions not only in India but also in other countries have become uncertain and unpredictable, which may have devastating effects on the agriculture production. India being an agricultural country, most of the farmers largely rely on monsoons and agricultural production is weather dependent. The environmental factors like temperature, humidity, moisture, precipitation and many other parameters keep on changing rapidly and unpredictably. This unpredictable nature, variability of climatic or weather conditions makes the life of farmers quite miserable as they are unable to take proper decisions at the right time. Thus, it is the need of the hour to have a real-time, local weather station which would keep the farmers informed well in advance about the prevailing weather conditions so that they can take appropriate decisions at the right time and save their crops from loss. Precision Agriculture (PA) is an art of using the latest available technologies in the agriculture domain so as to make traditional agriculture more profitable and sustainable while reducing the wastage of resources. The penetration of internet into India is very deep and very fast, especially due to the Jio mania by Reliance Jio Infocomm limited last year, high speed internet is now possible even in rural areas. This paper proposes a IoT based real-time local weather station for PA, that would provide farmers a means of automizing their agricultural practices (irrigation, fertilization, harvesting) at the right time. The proposed system would also aid the farmers to carry out the agricultural tasks on real-time bases, which in turn helps them to use the agricultural resources in efficient way and at the time when needed by the crops. The proposed weather system is a small step towards the development of PA system considering the Indian scenarios.

关键词： Meteorology Agriculture Temperature sensors Temperature measurement Internet of Things Monitoring

Upper limit on the Photoproduction Cross Section of the Spin-Exotic π1(1600)

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arXiv 2024年

作者： Afzal, F. Akondi, C.S. Albrecht, M. Amaryan, M. Arrigo, S. Arroyave, V. Asaturyan, A. Austregesilo, A. Baldwin, Z. Barbosa, F. Barlow, J. Barriga, E. Barsotti, R. Barton, d. Baturin, V. Berdnikov, V.V. Black, T. Boeglin, W. Boer, M. Briscoe, W.J. Britton, T. Cao, S. Chudakov, E. Chung, G. Cole, P.l. Cortes, O. Crede, V. dalton, M.M. darulis, d. deur, A. dobbs, S. dolgolenko, A. dugger, M. dzhygadlo, R. Ebersole, d. Edo, M. Egiyan, H. Erbora, T. Eugenio, P. Fabrizi, A. Fanelli, C. Fang, S. Fitches, J. Foda, A.M. Furletov, S. Gan, l. Gao, H. Gardner, A. Gasparian, A. Glazier, d. Gleason, C. Goryachev, V.S. Grube, B. Guo, J. Guo, l. Hernandez, J. Hernandez, K. Hoffman, N.d. Hornidge, d. Hou, G. Hurck, P. Hurley, A. Imoehl, W. Ireland, d.G. Ito, M.M. Jaegle, I. Jarvis, N.S. Jeske, T. Jing, M. Jones, R.T. Kakoyan, V. Kalicy, G. Khachatryan, V. Kourkoumelis, C. laduke, A. larin, I. lawrence, d. lersch, d.I. li, H. liu, B. livingston, K. lolos, G.J. lorenti, l. lyubovitskij, V. Ma, R. Mack, d. Mahmood, A. Marukyan, H. Matveev, V. McCaughan, M. McCracken, M. Meyer, C.A. Miskimen, R. Mitchell, R.E. Mizutani, K. Neelamana, V. Ng, l. Nissen, E. Orešić, S. Ostrovidov, A.I. Papandreou, Z. Paudel, C. Pedroni, R. Pentchev, l. Peters, K.J. Prather, E. Rakshit, S. Reinhold, J. Remington, A. Ritchie, B.G. Ritman, J. Rodriguez, G. Romanov, d. Saldana, K. Salgado, C. Schadmand, S. Schertz, A.M. Scheuer, K. Schick, A. Schmidt, A. Schumacher, R.A. Schwiening, J. Septian, N. Sharp, P. Shen, X. Shepherd, M.R. Sikes, J. Smith, A. Smith, E.S. Sober, d.I. Somov, A. Somov, S. Stevens, J.R. Strakovsky, I.I. Sumner, B. Suresh, K. Tarasov, V.V. Taylor, S. Teymurazyan, A. Thiel, A. Viducic, T. Whitlatch, T. Wickramaarachchi, N. Wunderlich, Y. Yu, B. Zarling, J. Zhang, Z. Zhou, X. Zihlmann, B. Polytechnic Sciences and Mathematics School of Applied Sciences and Arts Arizona State University TempeAZ85287 United States Department of Physics National and Kapodistrian University of Athens Athens15771 Greece Ruhr-Universität-Bochum Institut für Experimentalphysik BochumD-44801 Germany Helmholtz-Institut für Strahlen- und Kernphysik Universität Bonn BonnD-53115 Germany Department of Physics Carnegie Mellon University PittsburghPA15213 United States Department of Physics The Catholic University of America WashingtonDC20064 United States Department of Physics University of Connecticut StorrsCT06269 United States Department of Physics Duke University DurhamNC27708 United States Department of Physics Florida International University MiamiFL33199 United States Department of Physics Florida State University TallahasseeFL32306 United States Department of Physics The George Washington University WashingtonDC20052 United States School of Physics and Astronomy University of Glasgow GlasgowG12 8QQ United Kingdom GSI Helmholtzzentrum für Schwerionenforschung GmbH DarmstadtD-64291 Germany Institute of High Energy Physics Beijing100049 China Department of Physics Indiana University BloomingtonIN47405 United States National Research Centre Kurchatov Institute Moscow123182 Russia Department of Physics Lamar University BeaumontTX77710 United States Department of Physics University of Massachusetts AmherstMA01003 United States National Research Nuclear University Moscow Engineering Physics Institute Moscow115409 Russia Department of Physics Mount Allison University SackvilleNBE4L 1E6 Canada Department of Physics Norfolk State University NorfolkVA23504 United States Department of Physics North Carolina A&T State University GreensboroNC27411 United States Department of Physics and Physical Oceanography University of North Carolina at Wilmington WilmingtonNC28403 United States Department of Physics Old Dominion University No

The spin-exotic hybrid meson π1(1600) is predicted to have a large decay rate to the ωππ final state. Using 76.6 pb−1 of data collected with the GlueX detector, we measure the cross sections for the reactions γp → ωπ+π−p, γp → ωπ0π0p, and γp → ωπ−π0∆++ in the range Eγ = 8 − 10 GeV. Using isospin conservation, we set the first upper limits on the photoproduction cross sections of the π10(1600) and π1−(1600). We combine these limits with lattice calculations of decay widths and find that photoproduction of η′π is the most sensitive two-body system to search for the π1(1600). Copyright © 2024, The Authors. All rights reserved.

关键词： Bosons

Interstellar scintillation and polarization of PSR B0656+14 in the Monogem Ring

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arXiv 2022年

作者： Yao, Jumei Coles, William A. Manchester, Richard N. Stinebring, daniel R. Kramer, Michael Wang, Na li, di Zhu, Weiwei Feng, Yi Yuan, Jianping Wang, Pei Xinjiang Astronomical Observatory Chinese Academy of Sciences 150 Science 1-Street Urumqi Xinjiang830011 China Electrical and Computer Engineering University of California San Diego92093 United States Australia Telescope National Facility CSIRO Space and Astronomy P.O. Box 76 EppingNSW1710 Australia Department of Physics and Astronomy Oberlin College OberlinOH44074 United States Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 BonnD-53121 Germany Jodrell Bank Centre for Astrophysics The University of Manchester M13 9PL United Kingdom CAS Key Laboratory of FAST National Astronomical Observatories Chinese Academy of Sciences Chaoyang District Datun Road A.20 Beijing100101 China University of Chinese Academy of Sciences Beijing100049 China NAOC-UKZN Computational Astrophysics Centre University of KwaZulu-Natal Durban4000 South Africa Zhejiang Lab Zhejiang Hangzhou311121 China

High sensitivity interstellar scintillation and polarization observations of PSR B0656+14 made at three epochs over a year using the Five-hundred-meter Aperture Spherical radio Telescope (FAST) show that the scattering is dominated by two different compact regions. We identify the one nearer to the pulsar with the shell of the Monogem Ring, thereby confirming the association. The other is probably associated with the local Bubble. We find that the observed position angles of the pulsar spin axis and the space velocity are significantly different, with a separation of 19◦. 3±0◦. 8, inconsistent with a previously published near-perfect alignment of 1◦ ± 2◦. The two independent scattering regions are clearly defined in the secondary spectra which show two strong forward parabolic arcs. The arc curvatures imply that the scattering screens corresponding to the outer and inner arcs are located approximately 28 pc from PSR B0656+14 and 185 pc from the Earth, respectively. Comparison of the observed doppler profiles with electromagnetic simulations shows that both scattering regions are mildly anisotropic. For the outer arc, we estimate the anisotropy AR to be approximately 1.3, with the scattering irregularities aligned parallel to the pulsar velocity. For the outer arc, we compare the observed delay profiles with delay profiles computed from a theoretical strong-scattering model. Our results suggest that the spatial spectrum of the scattering irregularities in the Monogem Ring is flatter than Kolmogorov, but further observations are required to confirm this. © 2022, CC BY.

关键词： Pulsars

WAllABY Pilot Survey: The diversity of HI structural parameters in nearby galaxies

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arXiv 2023年

作者： Reynolds, T.N. Catinella, B. Cortese, l. deg, N. dénes, H. Elagali, A. For, B.-Q. Kamphuis, P. Kleiner, d. Koribalski, B.S. lee-Waddell, K. Murugeshan, C. Raja, W. Rhee, J. Spekkens, K. Staveley-Smith, l. van der Hulst, J.M. Wang, J. Westmeier, T. Wong, O.I. Bigiel, F. Bosma, A. Holwerda, B.W. leahy, d.A. Meyer, M.J. The University of Western Australia 35 Stirling Hwy CrawleyWA6009 Australia Australia Department of Physics Engineering Physics and Astronomy Queen’s University KingstonONK7L 3N6 Canada ASTRON The Netherlands Institute for Radio Astronomy Dwingeloo7991 PD Netherlands School of Biological Sciences The University of Western Australia PerthWA Australia Minderoo Foundation PerthWA Australia BochumD-44780 Germany INAF Osservatorio Astronomico di Cagliari Via della Scienza 5 CA Selargius09047 Italy CSIRO Space and Astronomy PO Box 76 EppingNSW1710 Australia School of Science Western Sydney University Locked Bag 1797 PenrithNSW2751 Australia CSIRO Space and Astronomy PO Box 1130 BentleyWA6102 Australia Department of Physics and Space Science Royal Military College of Canada PO Box 17000 Station Forces KingstonONK7L 2E1 Canada Kapteyn Astronomical Institute University of Groningen Landleven 12 Groningen9747AD Netherlands Kavli Institute for Astronomy and Astrophysics Peking University Beijing100871 China Argelander-Institut für Astronomie Universität Bonn Auf dem Hügel 71 Bonn53121 Germany Aix Marseille Université CNRS CNES LAM Marseille France Department of physics and astronomy University of Louisville Natural Science Building 102 LouisvilleKY40292 United States Department of Physics and Astronomy University of Calgary CalgaryABT2N 1N4 Canada

We investigate the diversity in the sizes and average surface densities of the neutral atomic hydrogen (H I) gas discs in ∼ 280 nearby galaxies detected by the Widefield ASKAP l-band legacy All-sky Blind Survey (WAllABY). We combine the uniformly observed, interferometric H I data from pilot observations of the Hydra cluster and NGC 4636 group fields with photometry measured from ultraviolet, optical and near-infrared imaging surveys to investigate the interplay between stellar structure, star formation and H I structural parameters. We quantify the H I structure by the size of the H I relative to the optical disc and the average H I surface density measured using effective and isodensity radii. For galaxies resolved by > 1.3 beams, we find that galaxies with higher stellar masses and stellar surface densities tend to have less extended H I discs and lower H I surface densities: the isodensity H I structural parameters show a weak negative dependence on stellar mass and stellar mass surface density. These trends strengthen when we limit our sample to galaxies resolved by > 2 beams. We find that galaxies with higher H I surface densities and more extended H I discs tend to be more star forming: the isodensity H I structural parameters have stronger correlations with star formation. Normalising the H I disc size by the optical effective radius (instead of the isophotal radius) produces positive correlations with stellar masses and stellar surface densities and removes the correlations with star formation. This is due to the effective and isodensity H I radii increasing with mass at similar rates while, in the optical, the effective radius increases slower than the isophotal radius. Our results are in qualitative agreement with previous studies and demonstrate that with WAllABY we can begin to bridge the gap between small galaxy samples with high spatial resolution H I data and large, statistical studies using spatially unresolved, single-dish data. Copyright © 2023, T

关键词： Galaxies

density functional theory (dFT) studies for quadrupole and octapole moments, field analysis by theoretical interactions by softwares and anti-diabetic (Ad), anti-oxidant (AO) bio-pharma properties of the dlA crystals

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AIP Conference Proceedings 2022年第1期2446卷

作者： J. Sheela R. Krishnaveni C. Shibana B. Maria Sumathi K. Senthil Kannan F. dayana lobo G. Flora U. S. Shoba 1School of Computer Science & Engineering VIT-AP University Vijayawada Andhra Pradesh -522 237 India 2Department of Microbiology Idhaya Collge for Women Kumbakonam – 612001 Tamilnadu India 3Department of Zoology St.Mary’s College – Autonomous Thoothukudi – 628001 Tamilnadu India 4Department of Botany St.Mary’s College – Autonomous Thoothukudi – 628001 Tamilnadu India 5Department of R&D / Physics Edayathangudy G.S Pillay Arts and Science College (Autonomous – Affiliated to Bharathidasan University – Tiruchirappalli – 620 024) Nagapattinam – 611 002 Tamilnadu India 6Department of Chemistry School of Foundational Sciences Kumaraguru College of Technology Coimbatore – 64104 Tamilnadu India

dlA crystals are of excellent optical material for the NlO utility and having enhanced projection by the computational structural predictions for entitled crystalline specimen and due to crystal combination it has anti-diabetic and anti-oxidant utility for the enrichment in bio applications by the concentration-inhibition values and by interactions of atoms by computational softwares.

关键词：

Possible origins of anomalous H i gas around MHONGOOSE galaxy, NGC 5068

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arXiv 2024年

作者： Healy, J. de Blok, W.J.G. Maccagni, F.M. Amram, P. Chemin, l. Combes, F. Holwerda, B.W. Kamphuis, P. Pisano, d.J. Schinnerer, E. Spekkens, K. Verdes-Montenegro, l. Walter, F. Adams, E.A.K. Gibson, B.K. Kleiner, d. Veronese, S. Zabel, N. English, J. Carignan, C. Oude Hoogeveensedijk 4 Dwingeloo7991 PD Netherlands Kapteyn Astronomical Institute University of Groningen PO Box 800 Groningen9700 AV Netherlands Department of Astronomy University of Cape Town Private Bag X3 Rondebosch7701 South Africa 09047 Italy Aix-Marseille Univ. CNRS CNES LAM 38 rue Frédéric Joliot Curie Marseille13338 France Instituto de Astrofisica Facultad de Ciencias Exactas Universidad Andres Bello Chile LERMA Observatoire de Paris PSL research Université CNRS Sorbonne Université Paris75104 France Collège de France 11 Place Marcelin Berthelot Paris75005 France University of Louisville Department of Physics and Astronomy 102 Natural Science Building LouisvilleKY40292 United States Bochum44780 Germany Max-Planck-Institut für Astronomie Königstuhl 17 HeidelbergD-69117 Germany Department of Physics and Space Science Royal Military College of Canada P.O. Box 17000 Station Forces Kingston ONK7K 7B4 Canada Department of Physics Engineering Physics and Astronomy Queen’s University KingstonONK7L 3N6 Canada Glorieta de la Astronomia s/n Granada18008 Spain E.A. Milne Centre for Astrophysics University of Hull HU6 7RX United Kingdom Department of Physics and Astronomy University of Manitoba WinnipegMBR3T 2N2 Canada Département de physique Université de Montréal Complexe des sciences MIL 1375 Avenue Thérèse-Lavoie-Roux MontréalQCH2V 0B3 Canada BP 7021 Ouaga03 Burkina Faso astron.nl

The existing reservoirs of neutral atomic hydrogen gas (H i) in galaxies are insufficient to have maintained the observed levels of star formation without some kind of replenishment. This refuelling of the H i reservoirs is likely to occur at column densities an order of magnitude lower than previous observational limits (NH i, limit ∼ 1019 cm−2 at 30′′ resolution over a linewidth of 20 km s−1). In this paper, we present recent deep H i observations of NGC 5068, a nearby isolated star-forming galaxy observed by MeerKAT as part of the MHONGOOSE survey. With these new data, we are able to detect low column density H i around NGC 5068 with a 3σ detection limit of NH i = 6.4 × 1017 cm−2 at 90′′ resolution over a 20 km s−1 linewidth. The high sensitivity and resolution of the MeerKAT data reveal a complex morphology of the H i in this galaxy – a regularly rotating inner disk coincident with the main star-forming disk of the galaxy, a warped outer disk of low column density gas (NH i 19 cm−2), in addition to clumps of gas on the north west side of the galaxy. We employ a simple two disk model that describe the inner and outer disks, and are able to identify anomalous gas that deviates from the rotation of the main galaxy. The morphology and the kinematics of the anomalous gas suggest a possible extra-galactic origin. We explore a number of possible origin scenarios that may explain the anomalous gas, and conclude that fresh accretion is the most likely scenario. © 2024, CC BY.

关键词： density of gases