Article
Astronomy & Astrophysics
Javiera Parada, Jeremy Heyl, Harvey Richer, Paul Ripoche, Laurie Rousseau-Nepton
Summary: A new distance determination method is introduced in this study, using carbon-rich asymptotic giant branch stars as standard candles and the Large and Small Magellanic Clouds as fundamental calibrators. By fitting the luminosity functions of these stars, the distance to a given galaxy can be estimated based on the resemblance to the LMC or SMC. Applied to NGC 6822 and IC 1613, the method yielded distance modulus values of 23.54 +/- 0.03 (stat) for NGC 6822 and 24.34 +/- 0.05 (stat) for IC 1613.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
O. C. Jones, C. Nally, M. J. Sharp, I McDonald, M. L. Boyer, M. Meixner, F. Kemper, A. M. N. Ferguson, S. R. Goldman, R. M. Rich
Summary: Using data from the Spitzer Space Telescope, variable stars in the compact elliptical galaxy M32 were identified, with 83 stars being candidate large-amplitude, long-period variables and 28 considered high-confidence variables. The majority of the variable stars were classified as asymptotic giant branch star candidates. The study found no evidence supporting the presence of a younger, infrared-bright stellar population in the M32 field.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Mojgan Aghakhanloo, Nathan Smith, Peter Milne, Jennifer E. Andrews, Alexei Filippenko, Jacob E. Jencson, David J. Sand, Schuyler D. Van Dyk, Samuel Wyatt, WeiKang Zheng
Summary: We analyze the photometric observations of SN 2000ch in NGC 3432 and find irregular and multipeaked outbursts with varying peak magnitude, duration, and shape. These outbursts, occurring since 2000, show a repeating period after 2008 and are attributed to violent interactions in an eccentric binary system. The observed change in orbital period may be due to mass lost in the outbursts. Continued attention to SN 2000ch is important as it may be heading towards a stellar merger or an SN-like explosion.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
William J. Henney, J. A. Lopez, Ma T. Garcia-Diaz, M. G. Richer
Summary: In this study, a comprehensive kinematic and morphological analysis of the asymmetric planetary nebula NGC 6210 was conducted, revealing the presence of five distinct ejection axes. Significant changes in outflow directions were detected during different stages of the planetary nebula phase, challenging existing models of planetary nebula formation and shaping.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
T. M. Lawlor
Summary: Late thermal pulse (LTP) stellar evolution models show rapid looping evolution in the Hertzsprung-Russell (HR) diagram between the asymptotic giant branch (AGB) and planetary nebula (PN) phase. LTP objects have a shorter duration than very late thermal pulses (VLTPs), but exhibit significant changes in temperature, luminosity, and size. We present stellar evolution calculations for LTP models with various metallicities and masses, focusing on a dense series (1.2 M-circle dot, Z = 0.015). We discuss different types of LTP eruptions based on temperature and present time-scales for heating, peak helium-burning luminosity, rapid decline, and cooling and brightening.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Michele Trabucchi, Peter R. Wood, Nami Mowlavi, Giada Pastorelli, Paola Marigo, Leo Girardi, Thomas Lebzelter
Summary: The study finds that non-linear models for long-period variability in luminous red giants can more accurately predict pulsation periods and have better agreement with observations compared to linear models. In addition to providing simple analytical relations based on mass and radius, the research also investigates the impact of turbulent viscosity on pulsation and possible effects of varying metallicity and carbon abundance.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Yoshifusa Ita, John W. Menzies, Patricia A. Whitelock, Noriyuki Matsunaga, Masaki Takayama, Yoshikazu Nakada, Toshihiko Tanabe, Michael W. Feast, Takahiro Nagayama
Summary: This paper aims to characterize the light variation properties of Mira variables in the Small Magellanic Cloud. Interesting phenomena such as phase lags and color phase inversions were observed. Conclusions regarding bolometric correction and period relations were drawn from the analysis of a multi-epoch data set.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Mei Ai, Ming Zhu, Jin-long Xu, Jie Wang, Ying-jie Jing, Hai-yang Yu, Peng Jiang
Summary: We present the results of new H I observations for the nearby galaxy NGC 4449 using the FAST. The observations detected more diffuse H I gas compared with previous studies. The results suggest interactions with NGC 4449B and DDO 125 as the possible origin of the irregularity of NGC 4449's huge H I gas halo.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
A. S. Gusev, E. Shimanovskaya, N. A. Zaitseva
Summary: This study investigates the spatial regularity in the distribution of young stellar population along the spiral arms of three late-type spiral galaxies. The analysis reveals that there are features of spatial regularity or quasi-regularity in the distribution of young stellar population, as well as regular chains of star formation regions in all arms of the galaxies. The characteristic scales of spacing range from 350 to 500 pc in different arms.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Adrian Bittner, Adriana de Lorenzo-Caceres, Dimitri A. Gadotti, Patricia Sanchez-Blazquez, Justus Neumann, Paula Coelho, Jesus Falcon-Barroso, Francesca Fragkoudi, Taehyun Kim, Ignacio Martin-Navarro, Jairo Mendez-Abreu, Isabel Perez, Miguel Querejeta, Glenn van de Ven
Summary: Inner bars are common structures in the local Universe and have a significant impact on the nuclear regions of disc galaxies. They exhibit distinct differences in metallicity and [alpha /Fe] abundances compared to the main bars, suggesting that inner bars are scaled down versions of the main bars in galaxies.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Anastasiya D. Yarovova, Oleg Egorov, Alexei Moiseev, Olga Maryeva
Summary: We discovered an unusual emission-line stellar-like object in the low-metallicity dwarf galaxy NGC 4068, characterized by high velocity dispersion, the presence of He II lambda 4686 angstrom line, and peculiarly low [S II]/[N II] fluxes ratio. Our observations suggest that this object is a single star with high bolometric luminosity surrounded by an expanding nebula. The peculiar nitrogen overabundance in the nebula indicates interaction between the star's ejecta and the interstellar medium, possibly a massive blue supergiant or Wolf-Rayet star.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
M. Ozdogan Ela, A. Akyuz, N. Aksaker, S. Avdan, I. Akkaya Oralhan, A. Vinokurov, S. Allak, Y. Solovyeva, K. Atapin, D. Bizyaev
Summary: The study uses archival data from the Hubble Space Telescope to search for optical candidates of ultraluminous X-ray sources in two dwarf galaxies, confirming associations with young star groups and HII complexes. The X-ray spectral data suggest that the sources are in luminous hard states, consistent with long-term observations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Nathan Roche, Jose M. Vilchez, Jorge Iglesias-Paramo, Polychronis Papaderos, Sebastian F. Sanchez, Carolina Kehrig, Salvador Duarte Puertas
Summary: Using PMAS Integral Field Unit, the southern component of the starburst galaxy NGC 4861, Markarian 59, was observed. The observations reveal a giant nebula and a concentration of stars with strong H a emission indicating a high star-formation rate. Spectral analysis suggests a bimodal star formation history, with Mrk 59 formed in ongoing starbursts. The emission mapping shows He II 4686 emission originating from both the central nebula and a more extended area.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
J. C. Motter, R. Riffel, T. Ricci, R. A. Riffel, T. Storchi-Bergmann, M. G. Pastoriza, A. Rodriguez-Ardila, D. Ruschel-Dutra, L. G. Dahmer-Hahn, N. Z. Dametto, M. R. Diniz
Summary: This study used adaptive optics assisted near-infrared observations to map the distribution and kinematics of ionized and molecular gas in the merger remnant galaxy NGC 34, revealing the presence of an AGN and a circumnuclear starburst ring. The emissions from [Fe II] and H-2 are enhanced in the nuclear region, likely due to a combination of photoionization by young stars, excitation by X-rays from the AGN, and shocks, indicating the presence of nuclear outflows.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Yuta Tarumi, Takuma Suda, Freeke van de Voort, Shigeki Inoue, Naoki Yoshida, Anna Frebel
Summary: By studying the production of barium and strontium in ultrafaint dwarf galaxies, it is found that efficient production of these elements is needed from the beginning of galaxy formation. The contribution of the s-process remains largely unknown, with rotating massive stars being a possible origin for barium in UFDs. Further observations are crucial to identify the origin of barium and strontium in UFDs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
M. Brunner, M. Mecina, M. Maercker, E. A. Dorfi, F. Kerschbaum, H. Olofsson, G. Rau
ASTRONOMY & ASTROPHYSICS
(2019)
Article
Astronomy & Astrophysics
Giada Pastorelli, Paola Marigo, Leo Girardi, Yang Chen, Stefano Rubele, Michele Trabucchi, Bernhard Aringer, Sara Bladh, Alessandro Bressan, Josefina Montalban, Martha L. Boyer, Julianne J. Dalcanton, Kjell Eriksson, Martin A. T. Groenewegen, Susanne Hofner, Thomas Lebzelter, Ambra Nanni, Philip Rosenfield, Peter R. Wood, Maria-Rosa L. Cioni
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2019)
Article
Astronomy & Astrophysics
L. Decin, W. Homan, T. Danilovich, A. de Koter, D. Engels, L. B. F. M. Waters, S. Muller, C. Gielen, D. A. Garcia-Hernandez, R. J. Stancliffe, M. Van de Sande, G. Molenberghs, F. Kerschbaum, A. A. Zijlstra, I. El Mellah
Correction
Astronomy & Astrophysics
L. Decin, W. Homan, T. Danilovich, A. de Koter, D. Engels, L. B. F. M. Waters, S. Muller, C. Gielen, D. A. Garcia-Hernandez, R. J. Stancliffe, M. Van de Sande, G. Molenberghs, F. Kerschbaum, A. A. Zijlstra, I. El Mellah
Article
Astronomy & Astrophysics
L. Doan, S. Ramstedt, W. H. T. Vlemmings, S. Mohamed, S. Hofner, E. De Beck, F. Kerschbaum, M. Lindqvist, M. Maercker, C. Paladini, M. Wittkowski
ASTRONOMY & ASTROPHYSICS
(2020)
Article
Astronomy & Astrophysics
S. Ramstedt, W. H. T. Vlemmings, L. Doan, T. Danilovich, M. Lindqvist, M. Saberi, H. Olofsson, E. De Beck, M. A. T. Groenewegen, S. Hofner, J. H. Kastner, F. Kerschbaum, T. Khouri, M. Maercker, R. Montez, G. Quintana-Lacaci, R. Sahai, D. Tafoya, A. Zijlstra
ASTRONOMY & ASTROPHYSICS
(2020)
Article
Astronomy & Astrophysics
M. Mecina, B. Aringer, W. Nowotny, M. A. T. Groenewegen, F. Kerschbaum, M. Brunner, H. -P. Gail
ASTRONOMY & ASTROPHYSICS
(2020)
Article
Astronomy & Astrophysics
M. Andriantsaralaza, S. Ramstedt, W. H. T. Vlemmings, T. Danilovich, E. De Beck, M. A. T. Groenewegen, S. Hofner, F. Kerschbaum, T. Khouri, M. Lindqvist, M. Maercker, H. Olofsson, G. Quintana-Lacaci, M. Saberi, R. Sahai, A. Zijlstra
Summary: The study aims to constrain the sizes and deviations from spherical symmetry in the CO circumstellar envelopes of different types of AGB stars. Results show that low-MLR S-type stars have CO-line-emitting CSE sizes between C-type and M-type stars, with no dependence on circumstellar density. The majority of S-type stars exhibit consistent spherical geometry in their CO CSEs, while some show signs of asymmetry requiring further investigation for insights into mass-loss processes.
ASTRONOMY & ASTROPHYSICS
(2021)
Proceedings Paper
Engineering, Aerospace
Rosario Cosentino, Mauro Focardi, Emanuele Galli, Manfred Steller, Carlo Del Vecchio Blanco, Stefano Pezzuto, Giovanni Giusi, Anna Maria Di Giorgio, David Biondi, Harald Jeszenszky, Harald Ottacher, Gunter Laky, Luca Serafini, Dominik Loidolt, Roland Ottensamer, Andrea Russi, Marina Vela Nunez, Armin Luntzer, Franz Kerschbaum
Summary: PLATO is a medium-class mission selected by ESA in 2014 for the purpose of discovering and characterizing various types of exoplanets. The spacecraft will operate from a halo orbit around L2, equipped with 26 small telescopes to observe target stars and process the data onboard.
SPACE TELESCOPES AND INSTRUMENTATION 2022: OPTICAL, INFRARED, AND MILLIMETER WAVE
(2022)
Proceedings Paper
Astronomy & Astrophysics
Rosario Cosentino, Mauro Focardi, Stefano Pezzuto, Giovanni Giusi, Emanuele Galli, Anna Maria Di Giorgio, Scige Liu, Alessio Traficante, David Biondi, Johan Hasiba, Karl Hofmann, Harald Jeszenszky, Gunter Laky, Harald Ottacher, Michael Steinberger, Manfred Steller, Jorge Tonfat, Robert Wallner, Sonja Neukirchner, Mario Leichtfried, Carlo Del Vecchio Blanco, Luca Serafini, Devitt Dini, Luca Pilato, Luca Toscano, Valfredo Zolesi, Manuel Guedel, Franz Kerschbaum, Roland Ottensamer, Armin Luntzer, Dominik Loidolt
Summary: PLATO, an M3 mission of ESA, aims to detect and characterize terrestrial exoplanets around bright solar-type stars. The payload consists of 26 small telescopes, with normal and fast data processing units and an instrument control unit for data routing. The architecture of the ICU, Avionic Validation Model testing, and results of the engineering model test are discussed in this paper.
SPACE TELESCOPES AND INSTRUMENTATION 2020: OPTICAL, INFRARED, AND MILLIMETER WAVE
(2021)
Proceedings Paper
Astronomy & Astrophysics
Dominik Loidolt, Roland Ottensamer, Armin Luntzer, Franz Kerschbaum, Harald Ottacher, Jorge Tonfat, Manfred Steller, Stefano Pezzuto, Mauro Focardi, Rosario Cosentino
Summary: PLATO is ESA's upcoming exoplanet-hunting mission, equipped with 26 cameras and 104 individual CCDs providing over 2,000 megapixels of optical sensitivity. A specialized hardware data compressor logic was developed to achieve high-speed lossless processing of imagette data.
SPACE TELESCOPES AND INSTRUMENTATION 2020: OPTICAL, INFRARED, AND MILLIMETER WAVE
(2021)
Article
Astronomy & Astrophysics
Kenneth H. Hinkle, Thomas Lebzelter, Francis C. Fekel, Oscar Straniero, Richard R. Joyce, Lisa Prato, Nicole Karnath, Nolan Habel
ASTROPHYSICAL JOURNAL
(2020)
Article
Astronomy & Astrophysics
Thomas Lebzelter, Kenneth H. Hinkle, Oscar Straniero, David L. Lambert, Catherine A. Pilachowski, Kristie A. Nault
ASTROPHYSICAL JOURNAL
(2019)
Article
Astronomy & Astrophysics
Kenneth H. Hinkle, Francis C. Fekel, Richard R. Joyce, Joanna Mikolajewska, Cezary Galan, Thomas Lebzelter
ASTROPHYSICAL JOURNAL
(2019)