Search Publications
Detection of Multiple Phase Space Overdensities of GSE Stars by Orbit Integration
Zhao, Gang; Chen, Yuqin; Li, Chengdong +5 more
In N-body simulations, nearly radial mergers can form shell-like overdensities in the sky position and phase space (r - v r ) due to the combination of dynamical friction and tidal stripping. The merger event of Gaia-Sausage-Enceladus (GSE) has provided a unique opportunity to study the shells in the phase space. To search for them, we…
The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. V. The Star Formation History of Sagittarius Dwarf Irregular Galaxy Derived from Long-period Variable Stars
Javadi, Atefeh; Saremi, Elham; van Loon, Jacco Th. +7 more
We conducted an optical monitoring survey of the Sagittarius dwarf irregular galaxy (SagDIG) during the period of 2016 June-2017 October, using the 2.5 m Isaac Newton Telescopeat La Palama. Our goal was to identify long-period variable stars (LPVs), namely, asymptotic giant branch stars (AGBs) and red supergiant stars, to obtain the star formation…
Steadiness of Coronal Heating
Judge, P. G.
The EUI instrument on the Solar Orbiter spacecraft has obtained the most stable, high-resolution images of the solar corona from its orbit with a perihelion near 0.4 au. A sequence of 360 images obtained at 17.1 nm, between 2022 October 25 19:00 and 19:30 UT, is scrutinized. One image pixel corresponds to 148 km at the solar surface. The widely he…
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…