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1. Circumgalactic Pressure Profiles Indicate Precipitation-limited Atmospheres for M _* ∼ 10 ⁹ –10 ^11.5 M _⊙

   https://doi.org/10.3847/2041-8213/ab2766  

   Voit, G. Mark; Donahue, Megan; Zahedy, Fakhri; Chen, Hsiao-Wen; Werk, Jessica; Bryan, Greg L.; O’Shea, Brian W. (July 2019, The Astrophysical Journal)
2. Ultracompact 4H-silicon carbide optomechanical resonator with f _m  ·  Q _m exceeding 10 ¹³   Hz

   https://doi.org/10.1364/PRJ.567674  

   Liu, Yuncong; Sun, Wenhan; Abiri, Hamed; Feng, Philip_X-L; Li, Qing (August 2025, Photonics Research)

   Silicon carbide (SiC) has great potential for optomechanical applications due to its outstanding optical and mechanical properties. However, challenges associated with SiC nanofabrication have constrained its adoption in optomechanical devices, as embodied by the considerable optical loss or lack of integrated optical access in existing mechanical resonators. In this work, we overcome such challenges and demonstrate a low-loss, ultracompact optomechanical resonator in an integrated 4H-SiC-on-insulator (4H-SiCOI) photonic platform for the first time, to our knowledge. Based on a suspended 4.3-μm-radius microdisk, the SiC optomechanical resonator features low optical loss (<1  dB/cm), a high mechanical frequencyf_mof 0.95×10⁹  Hz, a mechanical quality factorQ_mof 1.92×10⁴, and a footprint of <1×10⁻⁵  mm². The correspondingf_m·Q_mproduct is estimated to be 1.82×10¹³  Hz, which is among the highest reported values of optomechanical cavities tested in ambient environment at room temperature. In addition, the strong optomechanical coupling in the SiC microdisk enables coherent regenerative optomechanical oscillations at a threshold optical dropped power of 14 μW, which also supports efficient harmonic generation at increased power levels. With such competitive performance, we envision a range of chip-scale optomechanical applications to be enabled by the low-loss 4H-SiCOI platform. 

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3. Synthesis of N⁴ ‐Methylcytidine (m ⁴ C) and N⁴,N⁴‐ Dimethylcytidine (m ⁴ ₂ C) Modified RNA

   https://doi.org/10.1002/cpz1.248  

   Zheng, Ya Ying; Mao, Song; Sheng, Jia (September 2021, Current Protocols)
4. Layered and Cubic Semiconductors A Ga M ′ Q ₄ ( A ⁺ = K ⁺ , Rb ⁺ , Cs ⁺ , Tl ⁺ ; M ′ ⁴⁺ = Ge ⁴⁺ , Sn ⁴⁺ ; Q ^2– = S ^2– , Se ^2– ) and High Third-Harmonic Generation

   https://doi.org/10.1021/jacs.0c08638  

   Friedrich, Daniel; Byun, Hye Ryung; Hao, Shiqiang; Patel, Shane; Wolverton, Chris; Jang, Joon Ik; Kanatzidis, Mercouri G. (October 2020, Journal of the American Chemical Society)

   null (Ed.)
5. SDSS1335+0728: The awakening of a ∼10 ⁶   M _⊙ black hole

   https://doi.org/10.1051/0004-6361/202347957  

   Sánchez-Sáez, P; Hernández-García, L; Bernal, S; Bayo, A; Calistro_Rivera, G; Bauer, F E; Ricci, C; Merloni, A; Graham, M J; Cartier, R; et al (August 2024, Astronomy & Astrophysics)

   Context.The early-type galaxy SDSS J133519.91+072807.4 (hereafter SDSS1335+0728), which had exhibited no prior optical variations during the preceding two decades, began showing significant nuclear variability in theZwickyTransient Facility (ZTF) alert stream from December 2019 (as ZTF19acnskyy). This variability behaviour, coupled with the host-galaxy properties, suggests that SDSS1335+0728 hosts a ∼10⁶ M_⊙black hole (BH) that is currently in the process of “turning on”. Aims.We present a multi-wavelength photometric analysis and spectroscopic follow-up performed with the aim of better understanding the origin of the nuclear variations detected in SDSS1335+0728. Methods.We used archival photometry (from WISE, 2MASS, SDSS, GALEX, eROSITA) and spectroscopic data (from SDSS and LAMOST) to study the state of SDSS1335+0728 prior to December 2019, and new observations fromSwift, SOAR/Goodman, VLT/X-shooter, and Keck/LRIS taken after its turn-on to characterise its current state. We analysed the variability of SDSS1335+0728 in the X-ray/UV/optical/mid-infrared range, modelled its spectral energy distribution prior to and after December 2019, and studied the evolution of its UV/optical spectra. Results.From our multi-wavelength photometric analysis, we find that: (a) since 2021, the UV flux (fromSwift/UVOT observations) is four times brighter than the flux reported by GALEX in 2004; (b) since June 2022, the mid-infrared flux has risen more than two times, and theW1 − W2 WISE colour has become redder; and (c) since February 2024, the source has begun showing X-ray emission. From our spectroscopic follow-up, we see that (i) the narrow emission line ratios are now consistent with a more energetic ionising continuum; (ii) broad emission lines are not detected; and (iii) the [OIII] line increased its flux ∼3.6 years after the first ZTF alert, which implies a relatively compact narrow-line-emitting region. Conclusions.We conclude that the variations observed in SDSS1335+0728 could be either explained by a ∼10⁶ M_⊙AGN that is just turning on or by an exotic tidal disruption event (TDE). If the former is true, SDSS1335+0728 is one of the strongest cases of an AGN observed in the process of activating. If the latter were found to be the case, it would correspond to the longest and faintest TDE ever observed (or another class of still unknown nuclear transient). Future observations of SDSS1335+0728 are crucial to further understand its behaviour. 

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