Search Publications

Unresolved z 8 Point Sources and Their Impact on the Bright End of the Galaxy Luminosity Function
DOI: 10.3847/1538-4357/ac8874 Bibcode: 2022ApJ...936..167I

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…

2022 The Astrophysical Journal
eHST 5
Revisit of Open Clusters UPK 39, UPK 41, and PHOC 39: A New Binary Open Cluster Found
DOI: 10.3847/1538-3881/ac8545 Bibcode: 2022AJ....164..132Y

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…

2022 The Astronomical Journal
Gaia 5
Yellow Post-asymptotic-giant-branch Stars as Standard Candles. I. Calibration of the Luminosity Function in Galactic Globular Clusters
DOI: 10.3847/1538-4357/ac674d Bibcode: 2022ApJ...930..145C

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…

2022 The Astrophysical Journal
Gaia 5
The miniJPAS Survey: Detection of the double-core Lyα morphology for two high-redshift QSOs
DOI: 10.1051/0004-6361/202244711 Bibcode: 2022A&A...668A.148R

Diego, J. M.; Hernán-Caballero, A.; Mendes de Oliveira, C. +30 more

Context. The Lyα emission is an important tracer of neutral gas in a circum-galactic medium (CGM) around high-z quasi-stellar objects (QSOs). The origin of Lyα emission around QSOs is still under debate, bringing on significant implications for galaxy formation and evolution.
Aims: In this paper, we study Lyα nebulae around two high redshift …

2022 Astronomy and Astrophysics
eHST 5
X-ray spectral-timing variability of 1A 0535+262 during the 2020 giant outburst
DOI: 10.1051/0004-6361/202142716 Bibcode: 2022A&A...659A.178R

Zhang, S.; Reig, P.; Ma, R. C. +3 more

Context. The Be/X-ray binary 1A 0535+262 underwent a giant X-ray outburst in November 2020, peaking at ∼1 × 1038 erg s−1 (1-100 keV, 1.8 kpc), the brightest outburst recorded for this source so far. The source was monitored over two orders of magnitude in luminosity with Insight-HXMT, which allowed us to probe the X-ray varia…

2022 Astronomy and Astrophysics
Gaia 5
First evidence of a stripped star cluster from the Small Magellanic Cloud
DOI: 10.1093/mnras/stac1980 Bibcode: 2022MNRAS.515.4005P

Piatti, Andrés E.; Lucchini, Scott

We present results on the recently discovered stellar system YMCA-1, for which physical nature and belonging to any of the Magellanic System galaxies have been irresolutely analysed. We used SMASH and Gaia Early Data Release 3 data sets to conclude that we are dealing with a small star cluster. Its reddening-free, field star decontaminated colour-…

2022 Monthly Notices of the Royal Astronomical Society
Gaia 5
Study of Slow-Mode Shock Formation and Particle Acceleration in the Symmetric Magnetic Reconnection Based on Hybrid Simulations
DOI: 10.1029/2021JA030066 Bibcode: 2022JGRA..12730066W

Seki, K.; Amano, T.; Walia, N. K.

The structure of the magnetic reconnection region and the acceleration mechanism of particles as they traverse from upstream into the reconnection exhaust are explored using 2.5D hybrid simulations. The reconnection boundary was analyzed using the Rankine-Hugoniot conditions and the six specific conditions for slow-mode shocks. We observe that the…

2022 Journal of Geophysical Research (Space Physics)
Cluster 5
A Review of Cluster Wideband Data Multi-Spacecraft Observations of Auroral Kilometric Radiation
DOI: 10.1029/2021JA029499 Bibcode: 2022JGRA..12729499Y

Pickett, J. S.; Yearby, K. H.

We review important advances in the understanding of auroral kilometric radiation (AKR) resulting from observations by the Wideband Data instruments on the four Cluster spacecraft. AKR is an intense radio emission originating in the Earth's auroral regions with frequencies typically in the range 50-700 kHz, usually observed from space. It is now w…

2022 Journal of Geophysical Research (Space Physics)
Cluster 5
The Smallest Scale of Hierarchy Survey (SSH) - II. Extended star formation and bar-like features in the dwarf galaxy NGC 3741: recent merger or ongoing gas accretion?
DOI: 10.1093/mnras/stac541 Bibcode: 2022MNRAS.512.1781A

Bacchini, C.; Cignoni, M.; Tosi, M. +12 more

Using Large Binocular Telescope deep imaging data from the Smallest Scale of Hierarchy Survey (SSH) and archival Hubble Space Telescope data, we reveal the presence of two elongated stellar features contiguous to a bar-like stellar structure in the inner regions of the dwarf irregular galaxy NGC 3741. These structures are dominated by stars younge…

2022 Monthly Notices of the Royal Astronomical Society
eHST 5
South Pole Station Ground-Based and Cluster Satellite Measurements of Leaked and Escaping Auroral Kilometric Radiation
DOI: 10.1029/2021JA029399 Bibcode: 2022JGRA..12729399L

Yearby, Keith; Pickett, Jolene S.; LaBelle, James

Previous work suggests that Auroral Kilometric Radiation (AKR) leaks to low altitudes. To investigate this phenomenon, wideband wave measurements have been conducted simultaneously at South Pole, Antarctica, and at the Cluster satellites, during 35 intervals in 2018-2020. Leaked AKR is observed ∼5% of the time at South Pole and escaping AKR ∼31% o…

2022 Journal of Geophysical Research (Space Physics)
Cluster 5