Search Publications
Star Formation in the Dwarf Seyfert Galaxy NGC 4395: Evidence for Both AGN and SN Feedback?
Stalin, C. S.; Nandi, Payel; Saikia, D. J. +5 more
We present a detailed multiwavelength study of star formation in the dwarf galaxy NGC 4395, which hosts an active galactic nucleus (AGN). From our observations with the Ultra-Violet Imaging Telescope, we have compiled a catalog of 284 star-forming (SF) regions, out of which we could detect 120 SF regions in Hα observations. Across the entire galax…
Multithermal Jet Formation Triggered by Flux Emergence
Li, Xiaohong; Keppens, Rony; Zhou, Yuhao
Flux emergence is responsible for various solar eruptions. Combining observation and simulations, we investigate the influence of flux emergence at one footpoint of an arcade on coronal rain as well as induced eruptions. The emergence changes the pressure in the loops, and the internal coronal rain all moves to the other side. The emerging flux re…
IC 5146 Dark Streamer: The First Reliable Candidate of Edge Collapse, Hub-filament Systems, and Intertwined Sub-filaments
Men'shchikov, A.; Dewangan, L. K.; Baug, T. +5 more
The paper presents an analysis of multiwavelength data of a nearby star-forming site, the IC 5146 dark streamer (d ~ 600 pc), which has been treated as a single and long filament, fl. Two hub-filament systems (HFSs) are known to exist toward the eastern and the western ends of fl. Earlier published results favor simultaneous evidence of HFSs and e…
Model-independent Mass Reconstruction of the Hubble Frontier Field Clusters with MARS Based on Self-consistent Strong-lensing Data
Jee, M. James; Cha, Sangjun
We present a new strong-lensing (SL) mass reconstruction of the six Hubble Frontier Fields (HFF) clusters with the MAximum-entropy ReconStruction (MARS) algorithm. MARS is a new free-form inversion method, which suppresses spurious small-scale fluctuations while achieving excellent convergence in positions of multiple images. For each HFF cluster,…
The JCMT BISTRO Survey: Studying the Complex Magnetic Field of L43
Zhang, Yapeng; Pattle, Kate; Karoly, Janik +155 more
We present observations of polarized dust emission at 850 µm from the L43 molecular cloud, which sits in the Ophiuchus cloud complex. The data were taken using SCUBA-2/POL-2 on the James Clerk Maxwell Telescope as a part of the BISTRO large program. L43 is a dense ( ${N}_{{{\rm{H}}}_{2}}\sim {10}^{22}$ -1023 cm-2) compl…
Constraining the AGN Luminosity Function from JWST with the X-Ray Background
Loeb, Abraham; Padmanabhan, Hamsa
We predict the X-ray background (XRB) expected from the population of quasars detected by the James Webb Space Telescope spectroscopic surveys over the redshift range z ~ 4-7. We find that the measured UV emissivities imply a ~10 times higher unresolved XRB than constrained by current experiments. We illustrate the difficulty of simultaneously mat…
Origins of the Evil Eye: M64's Stellar Halo Reveals the Recent Accretion of an SMC-mass Satellite
Bell, Eric F.; Monachesi, Antonela; Bailin, Jeremy +9 more
M64, often called the "Evil Eye" galaxy, is unique among local galaxies. Beyond its dramatic, dusty nucleus, it also hosts an outer gas disk that counter-rotates relative to its stars. The mass of this outer disk is comparable to the gas content of the Small Magellanic Cloud (SMC), prompting the idea that it was likely accreted in a recent minor m…
Mass Function of a Young Cluster in a Low-metallicity Environment. Sh 2-209
Kobayashi, Naoto; Izumi, Natsuko; Saito, Masao +2 more
We present deep near-infrared (NIR) imaging of Sh 2-209 (S209), a low-metallicity ([O/H] = -0.5 dex) H II region in the Galaxy. From the NIR images, combined with astrometric data from Gaia EDR3, we estimate the distance to S209 to be 2.5 kpc. This is close enough to enable us to resolve cluster members clearly (≃1000 au separation) down to a mass…
Investigating Pre-eruptive Magnetic Properties at the Footprints of Erupting Magnetic Flux Ropes
Qiu, Jiong; Wang, Yuming; Liu, Rui +4 more
It is well established that solar eruptions are powered by free magnetic energy stored in the current-carrying magnetic field in the corona. It has also been generally accepted that magnetic flux ropes (MFRs) are a critical component of many coronal mass ejections. What remains controversial is whether MFRs are present well before the eruption. Ou…
Stars, Gas, and Star Formation of Distant Post-starburst Galaxies
Maseda, Michael V.; D'Eugenio, Francesco; van der Wel, Arjen +5 more
We present a comprehensive multiwavelength study of five post-starburst galaxies with M * > 1011 M ⊙ at z ~ 0.7, examining their stars, gas, and current and past star formation activities. Using optical images from the Subaru Telescope and Hubble Space Telescope, we observe a high incidence of companion galaxies…