Search Publications
Formation of the SDC13 Hub-filament System: A Cloud-Cloud Collision Imprinted on the Multiscale Magnetic Field
Wang, Jia-Wei; Koch, Patrick M.; Peretto, Nicolas +6 more
Hub-filament systems (HFSs) are potential sites of protocluster and massive star formation, and play a key role in mass accumulation. We report JCMT POL-2 850 µm polarization observations toward the massive HFS SDC13. We detect an organized magnetic field near the hub center with a cloud-scale "U-shape" morphology following the western edge …
Mass transfer and tidally tilted pulsation in the Algol-type system TZ Dra
Handler, G.; Leone, F.; De Cat, P. +6 more
Oscillating eclipsing Algols (oEAs) are remarkable systems that allow us to determine accurate fundamental stellar parameters (mass, radius) and probe the stellar interiors through pulsations. TZ Dra is an oEA system containing a δ Scuti component. To examine particular characteristics of such close systems including pulsations and mass transfer, …
Possible Ongoing Merger Discovered by Photometry and Spectroscopy in the Field of the Galaxy Cluster PLCK G165.7+67.0
Frye, Brenda L.; Conselice, Christopher J.; Yan, Haojing +17 more
We present a detailed study of the Planck-selected binary galaxy cluster PLCK G165.7+67.0 (G165; z = 0.348). A multiband photometric catalog is generated incorporating new imaging from the Large Binocular Telescope/Large Binocular Camera and Spitzer/IRAC to existing imaging. To cope with the different image characteristics, robust methods are appl…
The Environmental Dependence of Gas Properties in Dense Cores of a Protocluster at z 2.5 Revealed with ALMA
Suzuki, Tomoko L.; Koyama, Yusei; Kodama, Tadayuki +5 more
In a protocluster USS1558-003 at z = 2.53, galaxies in the dense cores show systematically elevated star-forming activity compared to those in less dense regions. To understand its origin, we look into the gas properties of the galaxies in the dense cores by conducting deep 1.1 mm observations with the Atacama Large Millimeter/submillimeter Array.…
Still at odds with conventional galaxy evolution: the star formation history of ultradiffuse galaxy Dragonfly 44
van Dokkum, Pieter; Forbes, Duncan A.; Romanowsky, Aaron J. +7 more
We study the star formation history (SFH) of the ultradiffuse galaxy (UDG) Dragonfly 44 (DF44) based on the simultaneous fit to near-ultraviolet to near-infrared photometry and high signal-to-noise optical spectroscopy. In fitting the observations, we adopt an advanced physical model with a flexible SFH and discuss the results in the context of th…
A First Look at Cepheids in a Type Ia Supernova Host with JWST
Casertano, Stefano; Riess, Adam G.; Yuan, Wenlong +1 more
We report the first look at extragalactic Cepheid variables with the James Webb Space Telescope (JWST), obtained from an archival observation of NGC 1365, host of SNIa 2012fr, a calibration path used to measure the Hubble constant. As expected, the high-resolution observations with NIRCam through F200W show better source separation from line-of-si…
Automatic Morphological Classification of Galaxies: Convolutional Autoencoder and Bagging-based Multiclustering Model
Fang, Guanwen; Lin, Zesen; Gu, Yizhou +1 more
In order to obtain morphological information of unlabeled galaxies, we present an unsupervised machine-learning (UML) method for morphological classification of galaxies, which can be summarized as two aspects: (1) the methodology of convolutional autoencoder (CAE) is used to reduce the dimensions and extract features from the imaging data; (2) th…
[C II] 158 µm line emission from Orion A. II. Photodissociation region physics
Wolfire, M. G.; Teyssier, D.; Goicoechea, J. R. +10 more
Context. The [C II] 158 µm fine-structure line is the dominant cooling line of moderate-density photodissociation regions (PDRs) illuminated by moderately bright far-ultraviolet (FUV) radiation fields. This makes this line a prime diagnostic for extended regions illuminated by massive stars.
Aims: We aim to understand the origin of [C I…
Correcting Stellar Flare Frequency Distributions Detected by TESS and Kepler
Yang, Ming; Zhou, Ji-Lin; Liu, Hui-Gen +1 more
The habitability of planets is closely connected with stellar activity, mainly the frequency of flares and the distribution of flare energy. Kepler and TESS find many flaring stars via precise time-domain photometric data, and the frequency and energy distribution of stellar flares on different types of stars are studied statistically. However, th…
Planetary nebulae with Wolf-Rayet-type central stars - III. A detailed view of NGC 6905 and its central star
Guerrero, M. A.; Toalá, J. A.; Todt, H. +6 more
We present a multiwavelength characterization of the planetary nebula (PN) NGC 6905 and its [Wolf-Rayet]-type ([WR]) central star (CSPN) HD 193949. Our Nordic Optical Telescope Alhambra Faint Object Spectrograph and Camera (ALFOSC) spectra and images unveil in unprecedented detail the high-ionization structure of NGC 6905. The high-quality spectra…