Search Publications
Universal Upper End of the Stellar Initial Mass Function in the Young and Compact LEGUS Clusters
Schaerer, Daniel; Smith, Linda J.; Calzetti, Daniela +21 more
We investigate the variation in the upper end of the stellar initial mass function (uIMF) in 375 young and compact star clusters in five nearby galaxies within ~5 Mpc. All the young stellar clusters (YSCs) in the sample have ages ≲ 4 Myr and masses above 500 M ⊙, according to standard stellar models. The YSC catalogs were produced from …
SOFIA and ALMA Investigate Magnetic Fields and Gas Structures in Massive Star Formation: The Case of the Masquerading Monster in BYF 73
Ryder, Stuart D.; Fissel, Laura M.; Pitts, Rebecca L. +4 more
We present Stratospheric Observatory For Infrared Astronomy (SOFIA) + Atacama Large Millimeter/submillimeter Array (ALMA) continuum and spectral-line polarization data on the massive molecular cloud BYF 73, revealing important details about the magnetic field morphology, gas structures, and energetics in this unusual massive star formation laborat…
Detections of [C II] 158 µm and [O III] 88 µm in a Local Lyman Continuum Emitter, Mrk 54, and Its Implications to High-redshift ALMA Studies
Hayes, Matthew; Inoue, Akio K.; Hashimoto, Takuya +17 more
We present integral field, far-infrared (FIR) spectroscopy of Mrk 54, a local Lyman continuum emitter, obtained with FIFI-LS on the Stratospheric Observatory for Infrared Astronomy. This is only the second time, after Haro 11, that [C II] 158 µm and [O III] 88 µm spectroscopy of the known LCEs have been obtained. We find that Mrk 54 ha…
Disentangling Stellar and Airglow Emission Lines from Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS) Spectra
France, Kevin; Youngblood, Allison; Bourrier, Vincent +1 more
H I Lyα (1215.67 Å) and the O I triplet (1302.17, 1304.86, and 1306.03 Å) are bright far-ultraviolet (FUV) emission lines that trace the stellar chromosphere. Observations of stellar Lyα and O I using the Hubble Space Telescope's (HST) most sensitive FUV spectrograph, the Cosmic Origins Spectrograph (COS), are contaminated with geocoronal emission…
Surveying the Giant H II Regions of the Milky Way with SOFIA: V. DR7 and K3-50
Lim, Wanggi; De Buizer, James M.; Radomski, James T. +1 more
We present our fifth set of results from our mid-infrared imaging survey of Milky Way Giant H II (GH II) regions with our detailed analysis of DR7 and K3-50. We obtained 20/25 and 37 µm imaging maps of both regions using the FORCAST instrument on the Stratospheric Observatory For Infrared Astronomy. We investigate the multiscale properties o…
Luminosity Outburst of a High-mass Young Stellar Object Triggered by the Surrounding Radiation Field
Liu, Jun-Ting; Chen, Xi; Li, Bin +8 more
We present observations of the 6.7 GHz methanol and 4.8 GHz formaldehyde masers toward the high-mass young stellar object G24.33+0.14 (hereafter G24). Our observations were conducted from 2019 to 2021 using the Shanghai Tianma 65 m Radio Telescope and the Very Large Array in response to the luminosity outburst event traced by these two species mas…
Three-dimensional Orbit of AC Her Determined: Binary-induced Truncation Cannot Explain the Large Cavity in This Post-AGB Transition Disk
Klement, Robert; Mérand, Antoine; Monnier, John D. +17 more
Some evolved binaries, namely post-asymptotic giant branch (AGB) binaries, are surrounded by stable and massive circumbinary disks similar to protoplanetary disks found around young stars. Around 10% of these disks are transition disks: they have a large inner cavity in the dust. Previous interferometric measurements and modeling have ruled out th…
Metallicity and Spectral Evolution of WASP 39b: The Limited Role of Hydrodynamic Escape
Miguel, Yamila; Kubyshkina, Daria; Louca, Amy J.
The recent observations on WASP-39 b by JWST have revealed hints of high metallicity within the atmosphere compared to its host star. There are various theories on how these high metallic atmospheres emerge. In this study, we closely investigate the impact of extreme escape in the form of hydrodynamic escape to see its impact on atmospheric metall…
Kinetic Alfvén Waves Excited by Multiple Free Energy Sources in the Magnetotail
Lakhina, G. S.; Singh, S. V.; Barik, K. C.
The generation of kinetic Alfvén waves (KAWs) is investigated through a three-component theoretical model incorporating ion beam and velocity shear as the sources of free energy in a non-Maxwellian κ-distributed plasmas. The model considers Maxwellian distributed background ions, drifting-Maxwellian beam ions, and κ-electrons as its constituent sp…
Examining the Properties of Low-luminosity Hosts of Type Ia Supernovae from ASAS-SN
Galbany, L.; Morrell, Nidia; Holoien, Thomas W. -S. +14 more
We present a spectroscopic analysis of 44 low-luminosity host galaxies of Type Ia supernovae (SNe Ia) detected by the All-Sky Automated Survey for Supernovae (ASAS-SN), using hydrogen, oxygen, and sulfur emission lines to measure metallicities and star formation rates. We find no statistically significant evidence that the star formation activity …