Search Publications
Direct Far-infrared Metal Abundances (FIRA). I. M101
Smith, J. D.; Groves, B.; Linden, S. T. +12 more
Accurately determining gas-phase metal abundances within galaxies is critical as metals strongly affect the physics of the interstellar medium. To date, the vast majority of widely used gas-phase abundance indicators rely on emission from bright optical lines, whose emissivities are highly sensitive to the electron temperature. Alternatively, dire…
Radiative losses in the chromosphere during a C-class flare
Leenaarts, J.; de la Cruz Rodríguez, J.; Díaz Baso, C. J. +2 more
Context. Solar flares release an enormous amount of energy (∼1032 erg) into the corona. A substantial fraction of this energy is transported to the lower atmosphere, which results in chromospheric heating. The mechanisms that transport energy to the lower solar atmosphere during a flare are still not fully understood.
Aims: We aim …
Variable Star Population in the Open Cluster NGC 6791 Observed by the Kepler Spacecraft
Németh, P.; Sahoo, S. K.; Baran, A. S. +3 more
We present the list of variable stars we found in the Kepler superstamp data covering approximately 9' from the central region of NGC 6791. We classified the variable stars based on the variability type and we established their cluster membership based on the available Gaia Early Data Release 3 astrometry, by means of the Bayesian Gaussian mixture…
MUSE spectroscopic observations of the young massive cluster NGC 1850
Bragaglia, A.; D'Orazi, V.; Carretta, E. +4 more
Context. The double cluster NGC 1850 in the Large Magellanic Cloud is the nearest young massive cluster of the Local Group with a mass similar to those of Galactic globular clusters. Recent studies have revealed an extended morphology of its main-sequence turn-off (MSTO), which can be interpreted as a spread in either age or internal rotation. In …
A Molecular Gas Ring Hidden in the Sombrero Galaxy
Fadda, Dario; Sutter, Jessica
We present Herschel, ALMA, and MUSE observations of the molecular ring of Messier 104, also known as the Sombrero galaxy. These previously unpublished archival data shed new light on the content of the interstellar medium of M104. In particular, molecular hydrogen measured by CO emission and dust measured by far-infrared light are uniformly distri…
Multiple components in the molecular outflow of the red supergiant NML Cyg
De Beck, E.; Andrews, H.; Hirvonen, P.
Despite their large impact on stellar and galactic evolution, the properties of outflows from red supergiants are not well characterized. We used the Onsala 20m telescope to perform a spectral survey at 3 and 4 mm (68-116 GHz) of the red supergiant NML Cyg, alongside the yellow hypergiant IRC + 10420. Our observations of NML Cyg were combined with…
Distance and age of the massive stellar cluster Westerlund 1 - II. The eclipsing binary W36
Damineli, Augusto; Mace, Gregory N.; Navarete, Felipe +3 more
Westerlund 1 (Wd 1) is one of the most relevant star clusters in the Milky Way to study massive star formation, although it is still poorly known. Here, we used photometric and spectroscopic data to model the eclipsing binary W36, showing that its spectral type is O6.5 III + O9.5 IV, hotter and more luminous than thought before. Its distance d
Unresolved z 8 Point Sources and Their Impact on the Bright End of the Galaxy Luminosity Function
Stiavelli, Massimo; Treu, Tommaso; Trenti, Michele +7 more
The distribution and properties of the first galaxies and quasars are critical pieces of the puzzle in understanding galaxy evolution and cosmic reionization. Previous studies have often excluded unresolved sources as potential low-redshift interlopers. We combine broadband color and photometric redshift analysis with morphological selections to i…
Revisit of Open Clusters UPK 39, UPK 41, and PHOC 39: A New Binary Open Cluster Found
Zhao, Gang; Yang, Yong; Zhao, Jingkun +2 more
We investigate the three open clusters near the Aquila Rift cloud, named UPK 39 (c1 hereafter), UPK 41 (c2 hereafter) in Sim et al. (2019), and PHOC 39 (c3 hereafter) in Hunt & Reffert (2021). Using photometric passpands, reddening, and extinction from Gaia DR3, we construct the color-absolute-magnitude diagram. Using isochrone fits, their age…
Yellow Post-asymptotic-giant-branch Stars as Standard Candles. I. Calibration of the Luminosity Function in Galactic Globular Clusters
Bond, Howard E.; Ciardullo, Robin; Siegel, Michael H. +1 more
We use the results of a survey for low-surface-gravity stars in Galactic (and LMC) globular clusters to show that "yellow" post-asymptotic-branch (yPAGB) stars are likely to be excellent extragalactic standard candles, capable of producing distances to early-type galaxies that are accurate to a couple of percent. We show that the mean bolometric m…