More Like this

1. Transition Region Brightening in a Moss Region and Their Relation with Lower Atmospheric Dynamics

   https://doi.org/10.3847/1538-4357/ad84e1  

   Ram, Bhinva; Samanta, Tanmoy; Chen, Yajie; Sterling, Alphonse C; Joshi, Jayant; Yurchyshyn, Vasyl; Chitta, Lakshmi Pradeep; Pant, Vaibhav (November 2024, The Astrophysical Journal)

   Abstract Small-scale brightenings (SBs) are commonly observed in the transition region (TR) that separates the solar chromosphere from the corona. These brightenings, omnipresent in active region patches known as “moss” regions, could potentially contribute to the heating of active region plasma. In this study, we investigate the properties of SB events in a moss region and their associated chromospheric dynamics, which could provide insights into the underlying generation mechanisms of the SBs. We analyzed the data sets obtained by coordinated observations using the Interface Region Imaging Spectrograph and the Goode Solar Telescope at Big Bear Solar Observatory. We studied 131 SB events in our region of interest and found that 100 showed spatial and temporal matches with the dynamics observed in the chromospheric Hαimages. Among these SBs, 98 of them were associated with spicules that are observed in Hαimages. Furthermore, detailed analysis revealed that one intense SB event corresponded to an Ellerman bomb (EB), while another SB event consisted of several recurring brightenings caused by a stream of falling plasma. We observed that Hαfar wings often showed flashes of strong brightening caused by the falling plasma, creating an Hαspectral profile similar to an EB. However, 31 of the 131 investigated SB events showed no noticeable spatial and temporal matches with any apparent features in Hαimages. Our analysis indicated that the predominant TR SB events in moss regions are associated with chromospheric phenomena primarily caused by spicules. Most of these spicules display properties akin to dynamic fibrils. 

   more » « less
2. The feasible region of hypergraphs

   https://doi.org/10.1016/j.jctb.2020.12.004  

   Liu, Xizhi; Mubayi, Dhruv (May 2021, Journal of Combinatorial Theory, Series B)

   null (Ed.)
3. The Service Rate Region Polytope

   https://doi.org/10.1137/23M1557829  

   Alfarano, Gianira N; Kılıç, Altan B; Ravagnani, Alberto; Soljanin, Emina (September 2024, SIAM Journal on Applied Algebra and Geometry)
4. Half-region depth for stochastic processes

   https://doi.org/10.1016/j.jmva.2015.07.012  

   Kuelbs, James; Zinn, Joel (December 2015, Journal of Multivariate Analysis)
5. The multi-region index of a knot

   https://doi.org/10.1142/S0218216520500224  

   Goodhill, Sarah; Lowrance, Adam M.; Gonzales, Valeria Munoz; Rattray, Jessica; Zeh, Amelia (April 2020, Journal of Knot Theory and Its Ramifications)

   Using region crossing changes, we define a new invariant called the multi-region index of a knot. We prove that the multi-region index of a knot is bounded from above by twice the crossing number of the knot. In addition, we show that the minimum number of generators of the first homology of the double branched cover of [Formula: see text] over the knot is strictly less than the multi-region index. Our proof of this lower bound uses Goeritz matrices. 

   more » « less