Molly Nies, Ismael Mireles, François Bouchy, Diana Dragomir, Belinda A Nicholson, Nora L Eisner, Sergio G Sousa, Karen A Collins, Steve B Howell, Carl Ziegler, Coel Hellier, Brett Addison, Sarah Ballard, Brendan P Bowler, César Briceño, Catherine A Clark, Dennis M Conti, Xavier Dumusque, Billy Edwards, Crystal L Gnilka, Melissa Hobson, Jonathan Horner, Stephen R Kane, John Kielkopf, Baptiste Lavie, Nicholas Law, Monika Lendl, Colin Littlefield, Huigen Liu, Andrew W Mann, Matthew W Mengel, Dominic Oddo, Jack Okumura, Enric Palle, Peter Plavchan, Angelica Psaridi, Nuno C Santos, Richard P Schwarz, Avi Shporer, Robert A Wittenmyer, Duncan J Wright, Hui Zhang, David Watanabe, Jennifer V Medina, Joel Villaseñor, Eric B Ting, Jessie L Christiansen, Joshua N Winn, Keivan G Stassun, S Seager, David W Latham, George R Ricker
{"title":"HD 21520 b: a warm sub-Neptune transiting a bright G dwarf","authors":"Molly Nies, Ismael Mireles, François Bouchy, Diana Dragomir, Belinda A Nicholson, Nora L Eisner, Sergio G Sousa, Karen A Collins, Steve B Howell, Carl Ziegler, Coel Hellier, Brett Addison, Sarah Ballard, Brendan P Bowler, César Briceño, Catherine A Clark, Dennis M Conti, Xavier Dumusque, Billy Edwards, Crystal L Gnilka, Melissa Hobson, Jonathan Horner, Stephen R Kane, John Kielkopf, Baptiste Lavie, Nicholas Law, Monika Lendl, Colin Littlefield, Huigen Liu, Andrew W Mann, Matthew W Mengel, Dominic Oddo, Jack Okumura, Enric Palle, Peter Plavchan, Angelica Psaridi, Nuno C Santos, Richard P Schwarz, Avi Shporer, Robert A Wittenmyer, Duncan J Wright, Hui Zhang, David Watanabe, Jennifer V Medina, Joel Villaseñor, Eric B Ting, Jessie L Christiansen, Joshua N Winn, Keivan G Stassun, S Seager, David W Latham, George R Ricker","doi":"10.1093/mnras/stae2079","DOIUrl":"https://doi.org/10.1093/mnras/stae2079","url":null,"abstract":"We report the discovery and validation of HD 21520 b, a transiting planet found with TESS and orbiting a bright G dwarf (V=9.2, Teff = 5871 ± 62 K, R⋆ = 1.04 ± 0.02 R⊙). HD 21520 b was originally alerted as a system (TOI-4320) consisting of two planet candidates with periods of 703.6 and 46.4 days. However, our analysis supports instead a single-planet system with an orbital period of 25.1292 ± 0.0001 days and radius of 2.70 ± 0.09 R⊕. Three full transits in sectors 4, 30 and 31 match this period and have transit depths and durations in agreement with each other, as does a partial transit in sector 3. We also observe transits using CHEOPS and LCOGT. SOAR and Gemini high-resolution imaging do not indicate the presence of any nearby companions, and Minerva-Australis and CORALIE radial velocities rule out an on-target spectroscopic binary. Additionally, we use ESPRESSO radial velocities to obtain a tentative mass measurement of $7.9^{+3.2}_{-3.0}, M_{hbox{$oplus $}}$, with a 3-σ upper limit of 17.7 M⊕. Due to the bright nature of its host and likely significant gas envelope of the planet, HD 21520 b is a promising candidate for further mass measurements and for atmospheric characterization.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"43 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The X-ray polarization of the jet in the vela PWN","authors":"Kuan Liu, Fei Xie, En-Wei Liang","doi":"10.1093/mnras/stae2068","DOIUrl":"https://doi.org/10.1093/mnras/stae2068","url":null,"abstract":"In this paper, we studied the X-ray polarization of the jet in the Vela Pulsar Wind Nebula (PWN). After the background subtraction, we found a high degree of polarization in the helical jet region, close to the upper limit allowed by the synchrotron radiation mechanism. This result indicates the magnetic field is highly ordered, even though the jet’s morphology is curved and varies rapidly, which suggests that the magnetic collimation process for the jet doesn’t introduce significant turbulence. The polarization angle is perpendicular to the symmetry axis of the nebula, consistent with the results from the magnetohydrodynamic numerical simulations. This finding sheds light on the underlying mechanisms related to the dynamics and evolution of the jet structures.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"108 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"SPIRou monitoring of the protostar V347 Aur: Binarity, magnetic fields, pulsed dynamo and accretion","authors":"J-F Donati, P I Cristofari, A Carmona, K Grankin","doi":"10.1093/mnras/stae2076","DOIUrl":"https://doi.org/10.1093/mnras/stae2076","url":null,"abstract":"We present in this paper an analysis of near-infrared observations of the 0.3 M⊙ protostar V347 Aur collected with the SPIRou high-resolution spectropolarimeter and velocimeter at the 3.6-m Canada-France-Hawaii Telescope from October 2019 to April 2023. From a set of 79 unpolarized and circularly polarized spectra of V347 Aur to which we applied Least-Squares Deconvolution (LSD), we derived radial velocities and longitudinal fields, along with their temporal variations over our monitoring campaign of 1258 d. Our data show that V347 Aur is an eccentric binary system with an orbital period 154.6 ± 0.7 d, experiencing strong to extreme accretion events near periastron. The companion is a 29.0 ± 1.6${rm M}_{2!_{4}}$ brown dwarf, a rare member of the brown dwarf desert of close companions around M dwarfs. We detect weak longitudinal fields (<100 G) at the surface of V347 Aur, significantly weaker than those of more evolved prototypical T Tauri stars. These fields show small-amplitude rotational modulation, indicating a mainly axisymmetric parent large-scale magnetic topology, and larger fluctuations at half the orbital period, suggesting that what we dub a ‘pulsed dynamo’ triggered by orbital motion and pulsed accretion operates in V347 Aur. Applying Zeeman-Doppler imaging to our circularly polarised LSD profiles, we find that the large-scale field of V347 Aur is mainly toroidal for most of our observations, with the toroidal component switching sign near periastron and apoastron. The weak large-scale dipole (≃ 30 G) is not able to disrupt the disc beyond 1.3 R⋆ even at the lowest accretion rates, implying longitudinally distributed (rather than localized) accretion at the surface of the protostar.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"49 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Vortex dynamics in various solar magnetic field configurations","authors":"Arjun Kannan, Nitin Yadav","doi":"10.1093/mnras/stae1990","DOIUrl":"https://doi.org/10.1093/mnras/stae1990","url":null,"abstract":"We investigate vortex dynamics in three magnetic regions, viz., Quiet Sun, Weak Plage, and Strong Plage, using realistic three-dimensional simulations from a comprehensive radiation-magnetohydrodynamics (MHD) code, MURaM. We find that the spatial extents and spatial distribution of vortices vary for different set-ups even though the photospheric turbulence responsible for generating vortices has similar profiles for all three regions. We investigate kinetic and magnetic swirling strength and find them consistent with the Alfvén wave propagation. Using a flux tube expansion model and linear MHD wave theory, we find that the deviation in kinetic swirling strength from the theoretically expected value is the highest for the Strong Plage, least for the Weak Plage, and intermediate for the Quiet Sun at chromospheric heights. It suggests that Weak Plage is the most favoured region for chromospheric swirls, though they are of smaller spatial extents than in Quiet Sun. We also conjecture that vortex interactions within a single flux tube in Strong Plage lead to an energy cascade from larger to smaller vortices that further result in much lower values of kinetic swirling strength than other regions. Fourier spectra of horizontal magnetic fields at 1 Mm height also show the steep cascade from large to smaller scales for Strong Plage. These findings indicate the potential of vortex-induced torsional Alfvén waves to travel higher in the atmosphere without damping for weaker magnetic regions such as the Quiet Sun, whereas vortices would result in dissipation and heating due to the vortex interactions in narrow flux tubes for the strongly magnetized regions such as Strong Plage.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"152 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Temporal Trends in Asteroid Behavior: A Machine Learning and N-Body Integration Approach","authors":"Chetan Abhijnanam Bora, Badam Singh Kushvah, Gunda Chandra Mouli, Saleem Yousuf","doi":"10.1093/mnras/stae2083","DOIUrl":"https://doi.org/10.1093/mnras/stae2083","url":null,"abstract":"Asteroids pose significant threats to Earth, necessitating early detection for potential deflection. Leveraging machine learning (ML), we classify asteroids into Near-Earth Asteroids (particularly Atens, Amors, Apollos, and Apoheles) and Non Near-Earth Asteroids, further categorizing them based on hazard potential. Training the seven models on a comprehensive dataset of 4687 asteroids, we achieve high accuracy in prediction. The predictive capability of these models is critical for informed decision-making in planetary defense strategies. We apply different regularization techniques to prevent overfitting and validate the models using a large unseen dataset. A rigorous long-term N-body integration spanning 1 million years is executed utilizing the Mercury N-body integrator to illuminate the evolution of asteroid properties over extended temporal scales. Following this integration process, the best-performing ML model is employed to classify asteroids based on their orbital characteristics and hazardous status respectively. Our findings highlight the effectiveness of ML in asteroid classification and prediction, paving the way for large-scale applications. By dividing a 1 million-year integration into intervals, we uncover temporal trends in asteroid behavior, revealing insights into hazard evolution and ejection patterns. Notably, initially, hazardous asteroids tend to transition to non-hazardous states over time, elucidating key dynamics in planetary defense. We illustrate these findings through plotted graphs, providing valuable insights into asteroid dynamics. These insights are instrumental in advancing our understanding of long-term asteroid behavior, with significant implications for future research and planetary protection efforts.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"9 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tanvi Goswamy, Andrew Collier Cameron, Thomas G Wilson
{"title":"Do anomalously-dense hot Jupiters orbit stealth binary stars?","authors":"Tanvi Goswamy, Andrew Collier Cameron, Thomas G Wilson","doi":"10.1093/mnras/stae2075","DOIUrl":"https://doi.org/10.1093/mnras/stae2075","url":null,"abstract":"The Wide Angle Search for Planets (WASP) survey used transit photometry to discover nearly 200 gas-giant exoplanets and derive their planetary and stellar parameters. Reliable determination of the planetary density depends on accurate measurement of the planet’s radius, obtained from the transit depth and photodynamical determination of the stellar radius. The stellar density, and hence the stellar radius are typically determined in a model-independent way from the star’s reflex orbital acceleration and the transit profile. Additional flux coming from the system due to a bright, undetected stellar binary companion can, however, potentially dilute the transit curve and radial velocity signal, leading to under-estimation of the planet’s mass and radius, and to overestimation of the planet’s density. In this study, we cross-check the published radii of all the WASP planet host stars, determined from their transit profiles and radial-velocity curves, against radiometric measurements of stellar radii derived from their angular diameters (via the Infrared Flux method) and trigonometric parallaxes. We identify eight systems showing radiometric stellar radii significantly greater than their published photodynamical values: WASPs 20, 85, 86, 103, 105, 129, 144 and 171. We investigate these systems in more detail to establish plausible ranges of angular and radial-velocity separations within which such ‘stealth binaries’ could evade detection, and deduce their likely orbital periods, mass ratios, and flux ratios. After accounting for the dilution of transit depth and radial velocity amplitude, we find that on average, the planetary densities for the identified stealth binary systems should be reduced by a factor of 1.3.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"9 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Constantina M Fotopoulou, Thorsten Naab, Natalia Lahén, Miha Cernetic, Tim-Eric Rathjen, Ulrich P Steinwandel, Jessica M Hislop, Stefanie Walch, Peter H Johansson
{"title":"The masses, structure and lifetimes of cold clouds in a high-resolution simulation of a low metallicity starburst","authors":"Constantina M Fotopoulou, Thorsten Naab, Natalia Lahén, Miha Cernetic, Tim-Eric Rathjen, Ulrich P Steinwandel, Jessica M Hislop, Stefanie Walch, Peter H Johansson","doi":"10.1093/mnras/stae2072","DOIUrl":"https://doi.org/10.1093/mnras/stae2072","url":null,"abstract":"We present an analysis of the cold gas phase in a low metallicity starburst generated in a high-resolution hydrodynamical simulation of a gas-rich dwarf galaxy merger as part of the griffin project. The simulations resolve (4 M⊙ gas phase mass resolution, ∼ 0.1 pc spatial resolution) the multi-phase interstellar medium with a non-equilibrium chemical heating/cooling network at temperatures below 104 K. Massive stars are sampled individually and interact with the ISM through the formation of HII regions and supernova explosions. In the extended starburst phase, the ISM is dominated by cold (Tgas < 300 K) filamentary clouds with self-similar internal structures. The clouds have masses of 102.6 - 105.6 M⊙ with a power law mass function, dN/dM∝Mα with α = −1.78( ± 0.08). They also follow the Larson relations, in good agreement with observations. We trace the lifecycle of the cold clouds and find that they follow an exponential lifetime distribution and an e-folding time of ∼ 3.5 Myr. Clouds with peak masses below 104 M⊙ follow a power law relation with their average lifetime $tau _mathrm{life} propto M^{0.3}_mathrm{max}$ which flattens out for higher cloud masses at <10 Myr. A similar relation exists between cloud size at peak mass and lifetime. This simulation of the evolution of a realistic galactic cold cloud population supports the rapid formation and disruption of star-forming clouds by stellar radiation and supernovae on a timescale less than 10 Myr.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"24 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
João P V Benedetti, Rogério Riffel, Tiago Ricci, Rogemar A Riffel, Miriani Pastoriza, Marina Trevisan, Luis G Dahmer-Hahn, Daniel Ruschel-Dutra, Alberto Rodríguez-Ardila, Anna Ferré-Mateu, Alexandre Vazdekis, João Steiner
{"title":"Digging deeper into NGC 6868 II: ionized gas and excitation mechanism","authors":"João P V Benedetti, Rogério Riffel, Tiago Ricci, Rogemar A Riffel, Miriani Pastoriza, Marina Trevisan, Luis G Dahmer-Hahn, Daniel Ruschel-Dutra, Alberto Rodríguez-Ardila, Anna Ferré-Mateu, Alexandre Vazdekis, João Steiner","doi":"10.1093/mnras/stae2077","DOIUrl":"https://doi.org/10.1093/mnras/stae2077","url":null,"abstract":"We studied the ionized gas in the inner region (∼680 × 470 pc2) of the galaxy NGC 6868 using Gemini/GMOS integral field unit observations. Channel maps reveal complex kinematics and morphology, indicating multiple processes at work in NGC 6868. Through emission-line fitting, we identified two ubiquitous components in our data: a narrow (σ ∼ 110 km s−1) tracing an ionized gas disc and a broad component (σ ∼ 300 km s−1) mainly associated with inflowing/outflowing gas. The derived V-band reddening shows a spatial distribution consistent with that obtained from stellar population synthesis, although with generally higher values. For the first time, we measured the electron temperature in NGC 6868, finding values ranging from ∼14000 K in the central region to ≳ 20000 K with an outward increasing temperature gradient. The electron density map exhibits an inverse relationship, with central values reaching Ne ∼ 4000 cm-3 for the broad component decreasing to Ne ∼ 100 cm-3 towards the edges of the field of view. Using BPT diagrams, we found that all spaxels are consistent with both AGN and shock ionization. However, when this information is combined with our kinematic and temperature findings, and further supported by the WHAN diagram, we argue that an AGN is the dominant ionisation mechanism in the central region of NGC 6868, while the extended outer component is ionized by a combination of hot low-mass evolved stars and shocks. According to our findings, shocks play a significant role in the ionization balance of this galaxy.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"9 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nency R Patel, Mathilde Jauzac, Anna Niemiec, David Lagattuta, Guillaume Mahler, Benjamin Beauchesne, Alastair Edge, Harald Ebeling, Marceau Limousin
{"title":"The KALEIDOSCOPE survey : A new strong and weak gravitational lensing view of the massive galaxy cluster MACS J1423.8+2404","authors":"Nency R Patel, Mathilde Jauzac, Anna Niemiec, David Lagattuta, Guillaume Mahler, Benjamin Beauchesne, Alastair Edge, Harald Ebeling, Marceau Limousin","doi":"10.1093/mnras/stae2069","DOIUrl":"https://doi.org/10.1093/mnras/stae2069","url":null,"abstract":"We present a combined strong and weak gravitational-lensing analysis of the massive galaxy cluster MACS J1423.8+2404 (z = 0.545, MACS J1423 hereafter), one of the most dynamically relaxed and massive cool-core clusters discovered in the MAssive Cluster Survey at z > 0.5. We combine high-resolution imaging from the Hubble Space Telescope (HST) in the F606W, F814W, and F160W pass-bands with spectroscopic observations taken as part of the KALEIDOSCOPE survey with the Multi-Unit Spectroscopic Explorer mounted on the Very Large Telescope. Our strong lensing analysis of the mass distribution in the cluster core is constrained by four multiple-image systems (17 individual images) within redshift range 1.779 < z < 2.840. Our weak-lensing analysis of the cluster outskirts, confined to the HST field of view, is based on a background galaxy catalogue with a density of 57 gal.arcmin−2. We measure a projected mass of M(R < 200 kpc) = (1.6 ± 0.05) × 1014 M⊙ from our strong-lensing model, and a projected mass of M(R < 640 kpc) = (6.6 ± 0.6) × 1014 M⊙ when combining with our the weak-lensing constraints. Our analysis of the cluster mass distribution yields no evidence of substructures, confirming the dynamically relaxed state of MACS J1423. Our work sets the stage for future analysis of MACS J1423 in the upcoming Canadian Near Infrared Imager and Stiltless Spectrograph Unbiased Cluster Survey for the James Webb Space Telescope.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"12 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I Heywood, A A Ponomareva, N Maddox, M J Jarvis, B S Frank, E A K Adams, M Baes, A Bianchetti, J D Collier, R P Deane, M Glowacki, S L Jung, H Pan, S H A Rajohnson, G Rodighiero, I Ruffa, M G Santos, F Sinigaglia, M Vaccari
{"title":"MIGHTEE-H i: Deep spectral line observations of the COSMOS field","authors":"I Heywood, A A Ponomareva, N Maddox, M J Jarvis, B S Frank, E A K Adams, M Baes, A Bianchetti, J D Collier, R P Deane, M Glowacki, S L Jung, H Pan, S H A Rajohnson, G Rodighiero, I Ruffa, M G Santos, F Sinigaglia, M Vaccari","doi":"10.1093/mnras/stae2081","DOIUrl":"https://doi.org/10.1093/mnras/stae2081","url":null,"abstract":"The MIGHTEE survey utilises the South African MeerKAT radio telescope to observe four extragalactic deep fields, with the aim of advancing our understanding of the formation and evolution of galaxies across cosmic time. MIGHTEE’s frequency coverage encompasses the $textrm {H}scriptstyle mathrm{I}$ line to a redshift of z ≃ 0.58, and OH megamasers to z ≃ 0.9.. We present the MIGHTEE-$textrm {H}scriptstyle mathrm{I}$ imaging products for the COSMOS field, using a total of 94.2 h on-target and a close-packed mosaic of 15 individual pointings. The spectral imaging covers two broad, relatively interference-free regions (960–1150 and 1290–1520 MHz) within MeerKAT’s L-band, with up to 26 kHz spectral resolution (5.5 km s−1 at z = 0). The median noise in the highest spectral resolution data is 74 μJy beam−1, corresponding to a 5σ $textrm {H}scriptstyle mathrm{I}$ mass limit of 108.5 M⊙ for a 300 km s−1 line at z = 0.07. The mosaics cover >4 deg2, provided at multiple angular resolution / sensitivity pairings, with an angular resolution for $textrm {H}scriptstyle mathrm{I}$ at z = 0 of 12″. We describe the spectral line processing workflow that will be the basis for future MIGHTEE-$textrm {H}scriptstyle mathrm{I}$ products, and validation of, and some early results from, the spectral imaging of the COSMOS field. We find no evidence for line emission at the position of the z = 0.376 $textrm {H}scriptstyle mathrm{I}$ line reported from the CHILES survey at a >94 per cent confidence level, placing a 3σ upper limit of 8.1 × 109 M⊙ on MHI for this galaxy. A public data release accompanies this article.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"3 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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