Search Publications
Metallicity Distribution Function of the Eridanus II Ultra-faint Dwarf Galaxy from Hubble Space Telescope Narrowband Imaging
Dolphin, Andrew E.; Martin, Nicolas; Starkenburg, Else +9 more
We use deep narrowband CaHK (F395N) imaging taken with the Hubble Space Telescope (HST) to construct the metallicity distribution function (MDF) of Local Group ultra-faint dwarf galaxy Eridanus II (Eri II). When combined with archival F475W and F814W data, we measure metallicities for 60 resolved red giant branch stars as faint as m F475W
A First Look into the Nature of JWST/MIRI 7.7 µm Sources from SMACS 0723
Rinaldi, Pierluigi; Caputi, Karina I.; Iani, Edoardo +1 more
Until now, our knowledge of the extragalactic universe at mid-infrared (mid-IR) wavelengths (>5 µm) was limited to rare active galactic nuclei and the brightest normal galaxies up to z ~ 3. The advent of JWST with its Mid-Infrared Instrument (MIRI) will revolutionize the ability of the mid-IR regime as a key wavelength domain to probe the…
Microlensing Events in the Galactic Plane Using the Zwicky Transient Facility
Duev, Dmitry A.; Riddle, Reed; Mróz, Przemek +10 more
Microlensing is a powerful technique to study the Galactic population of "dark" objects such as exoplanets both bound and unbound, brown dwarfs, low-luminosity stars, old white dwarfs, and neutron stars, and it is almost the only way to study isolated stellar-mass black holes. The majority of previous efforts to search for gravitational microlensi…
A Temperature Trend for Clouds and Hazes in Exoplanet Atmospheres
Swain, Mark R.; Estrela, Raissa; Roudier, Gael M.
The transmission spectra of exoplanet atmospheres observed with the Hubble Space Telescope (HST) in the near-infrared range (1.1-1.65 µm) frequently show evidence for some combination of clouds and hazes. Identification of systematic trends in exoplanet clouds and hazes is potentially important for understanding atmospheric composition and t…
The Magnetic Field in the Milky Way Filamentary Bone G47
Jackson, James M.; Sanhueza, Patricio; Guzmán, Andrés +21 more
Star formation primarily occurs in filaments where magnetic fields are expected to be dynamically important. The largest and densest filaments trace the spiral structure within galaxies. Over a dozen of these dense (~104 cm-3) and long (>10 pc) filaments have been found within the Milky Way, and they are often referred to …
The (Black Hole Mass)-(Spheroid Stellar Density) Relations: M BH-µ (and M BH-Σ) and M BH-ρ
Graham, Alister W.; Davis, Benjamin L.; Sahu, Nandini
This paper is the fourth in a series presenting (galaxy morphology, and thus galaxy formation)-dependent black hole (BH) mass, M BH, scaling relations. We have used a sample of 119 galaxies with directly measured M BH and host spheroid parameters obtained from multicomponent decomposition of, primarily, 3.6 µm Spitzer i…
Peculiar Radio-X-Ray Relationship in Active Stars
Ray, T. P.; Callingham, J. R.; Shimwell, T. W. +5 more
The empirical relationship between the nonthermal 5 GHz radio luminosity and the soft X-ray luminosity of active stellar coronae, canonically called the Güdel-Benz relationship, has been a cornerstone of stellar radio astronomy, as it explicitly ties the radio emission to the coronal heating mechanisms. The relationship extends from microflares on…
EXORCISM: A Spectroscopic Survey of Young Eruptive Variables (EXor and Candidates)
Rossi, A.; Testa, V.; Lorenzetti, D. +9 more
We present an optical/near-IR survey of 11 variable young stars (EXors and EXor candidates) aimed at deriving and monitoring their accretion properties. About 30 optical and near-infrared spectra ( ${\mathfrak{R}}\sim 1500\mbox{--}2000$ ) were collected between 2014 and 2019 with the Large Binocular Telescope (LBT). From the spectral analysis we h…
A Population of Luminous Globular Clusters and Stripped Nuclei with Elevated Mass to Light Ratios around NGC 5128
Forbes, Duncan A.; Caldwell, Nelson; Strader, Jay +8 more
The dense central regions of tidally disrupted galaxies can survive as ultracompact dwarfs (UCDs) that hide among the luminous globular clusters (GCs) in the halo of massive galaxies. An exciting confirmation of this model is the detection of overmassive black holes in the centers of some UCDs, which also lead to elevated dynamical mass-to-light r…
Observations of a Flare-ignited Broad Quasiperiodic Fast-propagating Wave Train
Liu, Ying D.; Hu, Huidong; Shen, Yuandeng +6 more
Large-scale extreme-ultraviolet (EUV) waves are frequently observed as an accompanying phenomenon of flares and coronal mass ejections (CMEs). Previous studies mainly focused on EUV waves with single wave fronts that are generally thought to be driven by the lateral expansion of CMEs. Using high spatiotemporal resolution multi-angle imaging observ…