Article
Astronomy & Astrophysics
Alice M. Eltvedt, T. Shanks, N. Metcalfe, B. Ansarinejad, L. F. Barrientos, R. Sharp, U. Malik, D. N. A. Murphy, M. Irwin, M. Wilson, D. M. Alexander, Andras Kovacs, Juan Garcia-Bellido, Steven Ahlen, David Brooks, Axel de la Macorra, Andreu Font-Ribera, Satya Gontcho a Gontcho, Klaus Honscheid, Aaron Meisner, Ramon Miquel, Jundan Nie, Gregory Tarle, Mariana Vargas-Magana, Zhimin Zhou
Summary: We present the VST ATLAS Quasar Survey, which includes over 1,229,000 quasar (QSO) candidates with 16 < g < 22.5 over an area of approximately 4,700 square degrees. The survey aims to reach a QSO sky density of 130 deg-2 for z < 2.2 and about 30 deg-2 for z > 2.2. The selection of candidates is guided by X-ray/UV/optical/MIR data in the William Herschel Deep Field (WHDF) and we find that about 25% of the QSOs are morphologically classified as optically extended. In terms of completeness and contamination, MIR, UV, and X-ray selections are 70-90% complete, with X-ray suffering less contamination than MIR and UV.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Carolina Queiroz, L. Raul Abramo, Natalia V. N. Rodrigues, Ignasi Perez-Rafols, Gines Martinez-Solaeche, Antonio Hernan-Caballero, Carlos Hernandez-Monteagudo, Alejandro Lumbreras-Calle, Matthew M. Pieri, Sean S. Morrison, Silvia Bonoli, Jonas Chaves-Montero, Ana L. Chies-Santos, L. A. Diaz-Garcia, Alberto Fernandez-Soto, Rosa M. Gonzalez Delgado, Jailson Alcaniz, Narciso Benitez, A. Javier Cenarro, Tamara Civera, Renato A. Dupke, Alessandro Ederoclite, Carlos Lopez-Sanjuan, Antonio Marin-Franch, Claudia Mendes de Oliveira, Mariano Moles, David Muniesa, Laerte Sodre Jr, Keith Taylor, Jesus Varela, Hector Vazquez Ramio
Summary: In this series of papers, we use machine learning methods to classify point-like sources and identify quasar candidates in the miniJPAS catalogue. Since no confirmed sample exists, we rely on mock catalogues for training these algorithms. In the first paper, we develop a pipeline to calculate synthetic photometry of quasars, galaxies, and stars using spectra from the Sloan Digital Sky Survey. These mock catalogues can also be adapted for other photometric surveys.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
V. A. Lepingwell, A. J. Bird, S. R. Gunn
Summary: This research presents two new approaches to aid in the production of future hard X-ray catalogues, reducing the reliance on human intervention during the detection of faint excesses in maps that contain systematic noise. A convolutional neural network has been trained to create a more sensitive source detection tool, while a method based on Bayesian reasoning is better able to combine detections from multiple observations. These improved techniques detect previously undetected sources in the data set used to derive the published catalogue.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
B. Posselt, A. Karastergiou, S. Johnston, A. Parthasarathy, L. S. Oswald, R. A. Main, A. Basu, M. J. Keith, X. Song, P. Weltevrede, C. Tiburzi, M. Bailes, S. Buchner, M. Geyer, M. Kramer, R. Spiewak, V. Venkatraman Krishnan
Summary: This study presents the largest survey of average profiles of radio pulsars to date, using the same telescope and data reduction software. The results show a significant correlation between the radio luminosity and the spin-down energy of pulsars, contradicting previous assumptions about population synthesis studies. Furthermore, the findings suggest that magnetic dipole braking may not be the dominant factor in the evolution of pulsar rotation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
L. Nakazono, C. Mendes de Oliveira, N. S. T. Hirata, S. Jeram, C. Queiroz, Stephen S. Eikenberry, A. H. Gonzalez, R. Abramo, R. Overzier, M. Espadoto, A. Martinazzo, L. Sampedro, F. R. Herpich, F. Almeida-Fernandes, A. Werle, C. E. Barbosa, L. Sodre Jr, E. Lima, M. L. Buzzo, A. Cortesi, K. Menendez-Delmestre, S. Akras, Alvaro Alvarez-Candal, A. R. Lopes, E. Telles, W. Schoenell, A. Kanaan, T. Ribeiro
Summary: This study presents a catalogue of stars, quasars, and galaxies in the Stripe 82 region using S-PLUS DR2 data, showing the advantages of a 12-band filter system for object classification. By training random forest classifiers with spectroscopically confirmed sources from SDSS DR16 and DR14Q, the study achieves high performance in classification.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
N. P. Gentile Fusillo, P-E Tremblay, E. Cukanovaite, A. Vorontseva, R. Lallement, M. Hollands, B. T. Gansicke, K. B. Burdge, J. McCleery, S. Jordan
Summary: In this study, a catalogue of white dwarf candidates was presented based on Gaia Early Data Release 3 (EDR3) and compared with samples from Sloan Digital Sky Survey (SDSS). The distribution of these candidates was mapped in the Gaia absolute magnitude-colour space, and a probability of being a white dwarf was calculated for over 1.3 million sources. High-confidence white dwarf candidates were selected based on these calculations and stellar parameters were estimated using synthetic atmospheric models. The catalogue was found to have an overall completeness limit of 93% for white dwarfs with G <= 20 mag and effective temperature (T-eff) > 7000 K at high Galactic latitudes.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
K. D. Neumann, T. W-S Holoien, C. S. Kochanek, K. Z. Stanek, P. J. Vallely, B. J. Shappee, J. L. Prieto, T. Pessi, T. Jayasinghe, J. Brimacombe, D. Bersier, E. Aydi, C. Basinger, J. F. Beacom, S. Bose, J. S. Brown, P. Chen, A. Clocchiatti, D. D. Desai, Subo Dong, E. Falco, S. Holmbo, N. Morrell, J. V. Shields, K. V. Sokolovsky, J. Strader, M. D. Stritzinger, S. Swihart, T. A. Thompson, Z. Way, L. Aslan, D. W. Bishop, G. Bock, J. Bradshaw, P. Cacella, N. Castro-Morales, E. Conseil, R. Cornect, I. Cruz, R. G. Farfan, J. M. Fernandez, A. Gabuya, J-L Gonzalez-Carballo, M. R. Kendurkar, S. Kiyota, R. A. Koff, G. Krannich, P. Marples, G. Masi, L. A. G. Monard, J. A. Munoz, B. Nicholls, R. S. Post, Z. Pujic, G. Stone, L. Tomasella, D. L. Trappett, W. S. Wiethoff
Summary: We catalogued and analyzed a sample of 2427 supernovae (SNe) discovered by ASAS-SN, including 443 bright SNe, 519 recovered SNe, and 516 additional SNe missed by ASAS-SN. Our focus was on the 984 SNe discovered or recovered in ASAS-SN g-band observations. We obtained updated data on peak magnitudes, redshifts, spectral classifications, and host galaxy identifications, and found that the ASAS-SN sample is almost complete up to m(peak) = 16.7 mag and 90% complete for m(peak) <= 17.0 mag, an improvement compared to the V-band sample.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Xinfeng Xu, Nahum Arav, Timothy Miller, Kirk T. Korista, Chris Benn
Summary: The study of quasar Q0059-2735 revealed a variety of outflow absorption features, including wide and narrow absorption lines formed by high and low-ionization transitions. By fitting the absorption troughs, the physical conditions of the outflows and the presence of iron-peak elements were determined. The research also uncovered the distance of the outflows to the central quasar and the smallest outflow deceleration in any known quasars.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Zhijie Qu, Hsiao-Wen Chen, Gwen C. Rudie, Fakhri S. Zahedy, Sean D. Johnson, Erin Boettcher, Sebastiano Cantalupo, Mandy C. Chen, Kathy L. Cooksey, David DePalma, Claude-Andre Faucher-Giguere, Michael Rauch, Joop Schaye, Robert A. Simcoe
Summary: This paper presents a systematic study of the photoionization and thermodynamic properties of the cool circumgalactic medium (CGM) around galaxies at redshift z less than or similar to 1, providing important insights into the gas density, temperature, and pressure of individual absorbing components and their non-thermal motions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Fakhri S. Zahedy, Hsiao-Wen Chen, Thomas M. Cooper, Erin Boettcher, Sean D. Johnson, Gwen C. Rudie, Mandy C. Chen, Sebastiano Cantalupo, Kathy L. Cooksey, Claude-Andre Faucher-Giguere, Jenny E. Greene, Sebastian Lopez, John S. Mulchaey, Steven Penton, Patrick Petitjean, Mary E. Putman, Marc Rafelski, Michael Rauch, Joop Schaye, Robert A. Simcoe, Gregory L. Walth
Summary: We present a systematic investigation of physical conditions and elemental abundances in four optically thick Lyman-limit systems (LLSs) at z = 0.36-0.6 discovered within the cosmic ultraviolet baryon survey (CUBS). The CUBS LLSs exhibit multicomponent kinematic structure and a complex mix of multiphase gas, with metal transitions from multiple ionization states. The cool-phase gas in LLSs has a median metallicity, and a wide range of inferred elemental abundance ratios indicate a diversity of chemical enrichment histories.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Thomas J. Cooper, Gwen C. Rudie, Hsiao-Wen Chen, Sean D. Johnson, Fakhri S. Zahedy, Mandy C. Chen, Erin Boettcher, Gregory L. Walth, Sebastiano Cantalupo, Kathy L. Cooksey, Claude-Andre Faucher-Giguere, Jenny E. Greene, Sebastian Lopez, John S. Mulchaey, Steven Penton, Patrick Petitjean, Mary E. Putman, Marc Rafelski, Michael Rauch, Joop Schaye, Robert A. Simcoe
Summary: This study investigates two partial Lyman limit systems (pLLSs) discovered in the Cosmic Ultraviolet Baryon Survey (CUBS), providing detailed information on the ionization analysis of multiphase gas in diverse galaxy environments. The data reveal kinematically aligned gas components with varying chemical abundances and densities, stressing the importance of considering the heterogeneous nature of circumgalactic gas in theoretical models. Additionally, survey data point to these systems being located near star-forming galaxies, highlighting the significance of studying the gas surrounding galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Iona Xia, Jian Ge, Kevin Willis, Yinan Zhao
Summary: Quasar absorption line analysis is crucial for studying gas and dust components, as well as the evolution and formation of galaxies. The number of known quasar Ca ii absorbers is relatively low, but using deep learning, researchers have developed an accurate and quick approach to search for Ca ii absorption lines. This method has resulted in the discovery of new absorbers and confirmed the existence of previously identified ones.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Xu Yang, Yi Hu, Zhaohui Shang, Bin Ma, Michael C. B. Ashley, Xiangqun Cui, Fujia Du, Jianning Fu, Xuefei Gong, Bozhong Gu, Peng Jiang, Xiaoyan Li, Zhengyang Li, Charling Tao, Lifan Wang, Lingzhe Xu, Shi-hai Yang, Ce Yu, Xiangyan Yuan, Ji-lin Zhou, Zhenxi Zhu
Summary: AST3-2 is the second telescope of the Antarctic Survey Telescopes designed for wide-field time-domain optical astronomy. Located at Dome A in Antarctica, it is considered the best optical astronomy site on Earth. This study presents the data and photometry results from the AST3-2 automatic survey in 2016, including 7 million stars and the detection of over 3500 variable stars, with 70 newly discovered. These new variables are classified into different types based on their light-curve features and stellar properties from surveys like StarHorse.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
M. Lacy, J. A. Surace, D. Farrah, K. Nyland, J. Afonso, W. N. Brandt, D. L. Clements, C. D. P. Lagos, C. Maraston, J. Pforr, A. Sajina, M. Sako, M. Vaccari, G. Wilson, D. R. Ballantyne, W. A. Barkhouse, R. Brunner, R. Cane, T. E. Clarke, M. Cooper, A. Cooray, G. Covone, C. D'Andrea, A. E. Evrard, H. C. Ferguson, J. Frieman, V Gonzalez-Perez, R. Gupta, E. Hatziminaoglou, J. Huang, P. Jagannathan, M. J. Jarvis, K. M. Jones, A. Kimball, C. Lidman, L. Lubin, L. Marchetti, P. Martini, R. G. McMahon, S. Mei, H. Messias, E. J. Murphy, J. A. Newman, R. Nichol, R. P. Norris, S. Oliver, I Perez-Fournon, W. M. Peters, M. Pierre, E. Polisensky, G. T. Richards, S. E. Ridgway, H. J. A. Rottgering, N. Seymour, R. Shirley, R. Somerville, M. A. Strauss, N. Suntzeff, P. A. Thorman, E. van Kampen, A. Verma, R. Wechsler, W. M. Wood-Vasey
Summary: The Vera C. Rubin Observatory's LSST survey will observe several Deep Drilling Fields in greater depth and more rapidly. The 'DeepDrill' survey, using the Spitzer Space Telescope, expands on previous observations in three DDFs. Observations reach a 5s point-source depth of 2 mu Jy in each of two bands, covering a total area of approximately 29 deg(2) and containing 2.35 million sources.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
F. Rastegarnia, M. T. Mirtorabi, R. Moradi, A. Vafaei Sadr, Y. Wang
Summary: Studying cosmological sources at their cosmological rest frames is crucial. In this study, a new neural network model called FNet is built to accurately estimate the redshift of quasars. FNet outperforms existing models in both accuracy and applicability.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Andrew Langford, Colin Littlefield, Peter Garnavich, Mark R. Kennedy, Simone Scaringi, Paula Szkody
Summary: Since its discovery in 1995, V2400 Oph has been distinguished from most known intermediate polar cataclysmic variables due to its proposed magnetic field strength and diskless accretion. To date, the exact accretion mechanism of the system is still unknown, and standard accretion models fail to accurately predict the peculiar behavior of its light curve.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Colin Littlefield, Jean-Pierre Lasota, Jean-Marie Hameury, Simone Scaringi, Peter Garnavich, Paula Szkody, Mark Kennedy, McKenna Leichty
Summary: This study reports the 27 day TESS light curve of V1025 Cen, an intermediate polar (IP) that exhibits 12 bursts of extremely short and repetitive accretion, validating the magnetically gated accretion mechanism in magnetized white dwarfs proposed by Spruit and Taam.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
P. Gandhi, D. A. H. Buckley, P. A. Charles, S. Hodgkin, S. Scaringi, C. Knigge, A. Rao, J. A. Paice, Y. Zhao
Summary: Astrometric noise combined with X-ray selection is used to identify accreting binaries in large surveys. By cross-matching the Gaia EDR3 catalogue with the Chandra Source Catalogue, a sample of approximately 6500 X-ray sources with significant astrometric noise is obtained. The X-ray detection efficiency for objects with significant noise is about 4.5 times higher than for objects with low noise. These objects, with significant noise, show distinct characteristics in color-magnitude space and include a higher fraction of known binaries, variables, and young stellar objects.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
K. Inight, B. T. Gansicke, D. Blondel, D. Boyd, R. P. Ashley, C. Knigge, K. S. Long, T. R. Marsh, J. McCleery, S. Scaringi, D. Steeghs, J. R. Thorstensen, T. Vanmunster, P. J. Wheatley
Summary: ASAS J071404+7004.3, a bright and nearby nova-like cataclysmic variable, was recently identified through various observations. Its period and mass transfer rate were determined, and rapidly changing winds from the accretion disk were found, with emission lines potentially originating from these winds. The variability of cataclysmic variables in the Gaia Hertzsprung-Russell diagram was also discussed.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Krystian Ilkiewicz, Joanna Mikolajewska, Simone Scaringi, Francois Teyssier, Kiril A. Stoyanov, Matteo Fratta
Summary: SU Lyn is a binary system consisting of a white dwarf and a red giant star. Although it is bright and variable at X-ray wavelengths, its optical counterpart appears as a single red giant with no prominent emission lines. Optical monitoring reveals that SU Lyn does not show significant photometric variability, but spectroscopic observations unveil a complex behavior, including strong emission line variability and variable reddening. Both X-ray and optical observations suggest that the components of SU Lyn only had a short period of interaction in the past twelve years.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
S. Scaringi, D. de Martino, D. A. H. Buckley, P. J. Groot, C. Knigge, M. Fratta, K. Ilkiewicz, C. Littlefield, A. Papitto
Summary: The study reports the discovery of abrupt drops in the optical luminosity of the accreting white dwarf binary system TW Pictoris, demonstrating fast switches between two distinct intensity modes likely related to the changing mass accretion rate onto the white dwarf. The findings suggest that in this binary system, the weak magnetic field of the white dwarf truncates the inner disc at the co-rotation radius in specific modes, leading to magnetically gated accretion bursts. The mode switching observed in TW Pictoris is similar to transitions seen in transitional millisecond pulsars, indicating a previously unrecognized phenomenon in accreting white dwarfs with potential connections to magnetic accretion onto neutron stars.
Article
Astronomy & Astrophysics
Colin Littlefield, D. W. Hoard, Peter Garnavich, Paula Szkody, Paul A. Mason, Simone Scaringi, Krystian Ilkiewicz, Mark R. Kennedy, Saul A. Rappaport, Rahul Jayaraman
Summary: We present long-duration, uninterrupted light curves of two magnetic cataclysmic variable stars with slightly desynchronized rotational frequencies. The first system, SDSS J084617.11+245344.1, exhibits a longer orbital period and a conspicuous beat period of 6.77 days. The second system, Paloma, displays a spin period of 2.27 hr and exhibits alternating single and double-humped light curves during the spin-orbit beat period. Rating: 8/10
ASTRONOMICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Colin Littlefield, Paul A. Mason, Peter Garnavich, Paula Szkody, John Thorstensen, Simone Scaringi, Krystian Ilkiewicz, Mark R. Kennedy, Natalie Wells
Summary: In this study, we report the discovery of an accreting white dwarf in a magnetic cataclysmic variable star (mCV) that displays asynchronous rotation despite having a high surface field strength and a short orbital period. This challenges the theoretical understanding of spin-period evolution.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Astronomy & Astrophysics
S. Scaringi, M. Monguio, C. Knigge, M. Fratta, B. Gaensicke, P. J. Groot, A. Rebassa-Mansergas, O. Toloza
Summary: This paper presents a sub-arcsec cross-match of Gaia DR3 with IGAPS and UKIDSS, resulting in a catalogue called XGAPS. The XGAPS catalogue provides additional precise photometry to Gaia photometry and has various applications, such as selecting Galactic targets for spectroscopic surveys and identifying specific Galactic populations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
M. Veresvarska, S. Scaringi
Summary: Flickering, or aperiodic broad-band variability, is important for understanding the geometry and dynamics of accretion flows. We have detected a low-frequency break in the ultracompact accreting white dwarf system SDSS J1908+3940, which provides a precedent for further studies and can help constrain simulations of accretion flows.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Arti Joshi, Nikita Rawat, Axel Schwope, J. C. Pandey, Simone Scaringi, D. K. Sahu, Srinivas M. Rao, Mridweeka Singh
Summary: In this study, we analyzed an Intermediate Polar, IGR J15094-6649, using optical data from TESS and X-ray data from Suzaku, NuSTAR, and Swift. We confirmed and refined the spin period of IGR J15094-6649 as 809.49584 +/- 0.00075 s and discovered a previously unidentified beat period of 841.67376 +/- 0.00082 s. The dominance of X-ray and optical spin pulse suggests disc-fed dominance accretion, while the presence of an additional beat frequency indicates flow along magnetic field lines. The energy-dependent spin pulsations in the low energy band are caused by photoelectric absorption, while complex absorbers produce low amplitude spin modulations via Compton scattering in the hard energy band.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
K. I. I. Koljonen, K. S. Long, J. H. Matthews, C. Knigge
Summary: Through VLT X-Shooter spectroscopy and Monte Carlo radiative transfer modeling, we investigate the formation of the spectrum in X-ray binary MAXI J1820+070. We find that the spectrum is mainly produced in the transition region between the radiation-driven UV and X-ray outflow and has electron densities consistent with the observed Balmer decrement.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Yue Zhao, Poshak Gandhi, Cordelia Dashwood Brown, Christian Knigge, Phil A. Charles, Thomas J. Maccarone, Pornisara Nuchvanichakul
Summary: The authors compiled a catalogue of X-ray binaries, including binaries with neutron stars or black holes and measured systemic radial velocities. They used Gaia and radio proper motions to integrate the Galactic orbits and infer the post-supernova 3D peculiar velocities. The study found a distribution of velocities with a low-velocity component and a high-velocity component, with significant correlations with binary total mass and orbital period.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
S. Scaringi, K. Breivik, T. B. Littenberg, C. Knigge, P. J. Groot, M. Veresvarska
Summary: This study assesses the significance of gravitational wave signals from the Galactic population of cataclysmic variables (CVs) for the Laser Interferometer Space Antenna (LISA). The results show that CVs can generate strong signals and have a significant impact on LISA's mission. Additionally, CVs contribute to the Galactic binary background of LISA and generate excess noise in the unresolved gravitational wave background.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)