Zobrazeno 1 - 10
of 488
pro vyhledávání: '"Friesen, A. K."'
Autor:
Chen, Michael Chun-Yuan, Di Francesco, James, Friesen, Rachel K., Pineda, Jaime E., Caselli, Paola, Ginsburg, Adam, Kirk, Helen, Punanova, Anna, Collaboration, the GAS
Observations suggest that filaments in molecular clouds can grow by mass accretion while forming cores via fragmentation. Here we present one of the first large sample studies of filament accretion using velocity gradient measurements of star-forming
Externí odkaz:
http://arxiv.org/abs/2410.16372
Autor:
Friesen, Rachel K., Jarvis, Emma
Most stars form in clusters and groups rather than in isolation. We present $\lesssim 5^{\prime\prime}$ angular resolution ($\sim 2000$ au, or 0.01 pc) Very Large Array NH$_3$ (1,1), (2,2), and (3,3) and 1.3 cm continuum emission observations of the
Externí odkaz:
http://arxiv.org/abs/2404.07259
Autor:
Taniguchi, Kotomi, Pineda, Jaime E, Caselli, Paola, Shimoikura, Tomomi, Friesen, Rachel K., Segura-Cox, Dominique M., Schmiedeke, Anika
Streamers bring gas from outer regions to protostellar systems and could change the chemical composition around protostars and protoplanetary disks. We have carried out mapping observations of carbon-chain species (HC$_3$N, HC$_5$N, CCH, and CCS) in
Externí odkaz:
http://arxiv.org/abs/2402.19099
Autor:
Petrashkevich, I. V., Punanova, A. F., Caselli, P., Sipilä, O., Pineda, J. E., Friesen, R. K., Korotaeva, M. G., Vasyunin, A. I.
In this work, we study deuterium fractionation in four starless cores in the low-mass star-forming region L1688 in the Ophiuchus molecular cloud. We study how the deuterium fraction ($R_D$) changes with environment, compare deuteration of ions and ne
Externí odkaz:
http://arxiv.org/abs/2401.04415
Autor:
Pandhi, A., Friesen, R. K., Fissel, L., Pineda, J. E., Caselli, P., Chen, M. C-Y., Di Francesco, J., Ginsburg, A., Kirk, H., Myers, P. C., Offner, S. S. R., Punanova, A., Quan, F., Redaelli, E., Rosolowsky, E., Scibelli, S., Seo, Y. M., Shirley, Y.
Studies of dense core morphologies and their orientations with respect to gas flows and the local magnetic field have been limited to only a small sample of cores with spectroscopic data. Leveraging the Green Bank Ammonia Survey alongside existing su
Externí odkaz:
http://arxiv.org/abs/2307.13022
Autor:
Chen, Michael Chun-Yuan, Di Francesco, James, Pineda, Jaime E., Offner, Stella S., Friesen, Rachel K.
Publikováno v:
The Astrophysical Journal, Volume 935, Issue 1, id.57, 16 pp (2022)
High-resolution observations of the Perseus B5 "core" have previously revealed that this subsonic region actually consists of several filaments that are likely in the process of forming a quadruple stellar system. Since subsonic filaments are thought
Externí odkaz:
http://arxiv.org/abs/2209.00659
Autor:
Pineda, Jaime E., Arzoumanian, Doris, André, Philippe, Friesen, Rachel K., Zavagno, Annie, Clarke, Seamus D., Inoue, Tsuyoshi, Chen, Che-Yu, Lee, Yueh-Ning, Soler, Juan D., Kuffmeier, Michael
The study of the development of structures on multiple scales in the cold interstellar medium has experienced rapid expansion in the past decade, on both the observational and the theoretical front. Spectral line studies at (sub-)millimeter wavelengt
Externí odkaz:
http://arxiv.org/abs/2205.03935
Autor:
Pineda, Jaime E., Harju, Jorma, Caselli, Paola, Sipilä, Olli, Juvela, Mika, Vastel, Charlotte, Rosolowsky, Erik, Burkert, Andreas, Friesen, Rachel K., Shirley, Yancy, Maureira, María José, Choudhury, Spandan, Segura-Cox, Dominique M., Güsten, Rolf, Punanova, Anna, Bizzocchi, Luca, Goodman, Alyssa A.
Spectral lines of ammonia, NH$_3$, are useful probes of the physical conditions in dense molecular cloud cores. In addition to advantages in spectroscopy, ammonia has also been suggested to be resistant to freezing onto grain surfaces, which should m
Externí odkaz:
http://arxiv.org/abs/2205.01201
Autor:
Singh, Ayushi, Matzner, Christopher D., Friesen, Rachel K., Martin, Peter G., Pineda, Jaime E., Rosolowsky, Erik W., Alves, Felipe, Chacón-Tanarro, Ana, Chen, Hope How-Huan, Chen, Michael Chun-Yuan, Choudhury, Spandan, Di Francesco, James, Keown, Jared, Kirk, Helen, Punanova, Anna, Seo, Youngmin, Shirley, Yancy, Ginsburg, Adam, Offner, Stella S. R., Arce, Héctor G., Caselli, Paola, Goodman, Alyssa A., Myers, Philip C., Redaelli, Elena
Dynamical studies of dense structures within molecular clouds often conclude that the most massive clumps contain too little kinetic energy for virial equilibrium, unless they are magnetized to an unexpected degree. This raises questions about how su
Externí odkaz:
http://arxiv.org/abs/2108.05367
The Core Mass Function in the Orion Nebula Cluster Region: What Determines the Final Stellar Masses?
Autor:
Takemura, Hideaki, Nakamura, Fumitaka, Kong, Shuo, Arce, Héctor G., Carpenter, John M., Ossenkopf-Okada, Volker, Klessen, Ralf, Sanhueza, Patricio, Shimajiri, Yoshito, Tsukagoshi, Takashi, Kawabe, Ryohei, Ishii, Shun, Dobashi, Kazuhito, Shimoikura, Tomomi, Goldsmith, Paul F., Sánchez-Monge, Álvaro, Kauffmann, Jens, Pillai, Thushara, Padoan, Paolo, Ginsberg, Adam, Smith, Rowan J., Bally, John, Mairs, Steve, Pineda, Jaime E., Lis, Dariusz C., Burkhart, Blakesley, Schilke, Peter, Chen, Hope How-Huan, Isella, Andrea, Friesen, Rachel K., Goodman, Alyssa A., Harper, Doyal A.
Applying dendrogram analysis to the CARMA-NRO C$^{18}$O ($J$=1--0) data having an angular resolution of $\sim$ 8", we identified 692 dense cores in the Orion Nebula Cluster (ONC) region. Using this core sample, we compare the core and initial stellar
Externí odkaz:
http://arxiv.org/abs/2103.08527