Shlosman, Isaac

Owned by UKY CCS RCD
Jun 09, 2024
5 min read


DLX RESEARCH PROJECTS in SHLOSMAN's GROUP:
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Formation and Evolution of High Redshift Galaxies in the Universe.

This project deals with state-of-the-art numerical simulations of galaxy evolution in a cosmological context. Two collisionless fluids' (dark matter and stars) and a dissipative fluid (gas) are followed using two evolutionary codes: FTM 4.5 (Heller and Shlosman) and GADGET-3 (Springel). GADGET-3 is a hybrid N-body/Smooth Particle Hydrodynamics (SPH) code. The gravitational interactions are computed via hierarchical multipole expansion (the Tree). GADGET-3 applies the Tree method to small scales, using the particle-mesh for long-range gravitational forces, to increase the accuracy. It has a superior scalability to take the advantage of massively parallel machines due to its novel domain-decomposition method which guarantees a force that is independent of the processor number. The SPH uses a kernel interpolation technique to obtain the continuous fluid properties. The SPH takes advantage of the Lagrangian method and is particularly suitable when following the growth of structure by gravity, achieving automatic increase in the resolution of assembling objects. This allows to address the dynamic range --- a major problem when modeling the buildup of structure in the universe. Runs on 100s of processors.

FTM-4.5 is a numerical code similar to GADGET-3 (i.e., N-body/SPH), which computes gravitational forces using falcON force solver --- a Tree code with complexity O(N). It is about 10 times faster than optimally coded tree codes in public domain, and faster than the public version of GADGET2. FTM typically runs on 100s CPUs.

Upgraded Numerical codes to GADGET-4, 05/25/2021.

Personnel:

Dr. E. Romano-Diaz - (lead, postdoc)
Dr. J.-H. Choi - (postdoc)
Dr. R. Sadoun - (postdoc)
Da Bi (grad student)
Dr. I. Shlosman - PI (UK, faculty)
Dr. Yang Luo (PostDoc)

Volker Springel, External user, Added 01/10/2022 EXSEDE

Xingchen Li, Added on MCC cluster, 10/23/2023 


Funding:

Support: NSF, NASA/Astrophysics Theory Program

Formation of Supermassive Black Holes Seeds in the Early Universe.

This project deals with the computational issues of a gravitational collapse within the cosmological context. It is using the ENZO-2.1 code. This is an adaptive mesh refinement (AMR) code (hydro/N-body), where the fluid is discretized onto an Eulerian grid. It implements the block-structured AMR algorithm. In cells where certain criteria are violated (e.g., overdensity, Jeans parameter, slopes of fluid quantities) higher-resolution regions are inserted. This process is applied dynamically, to ensure adequate resolution of physical processes on all scalelengths. This is especially important in collapse simulations where the innermost regions evolve more quickly. The entire simulation is coupled and large-scale torques, inflow, and dark matter halo properties are self-consistently included. Mesh refinement can be continued to an arbitrary level, based on criteria involving a combination of dark matter and/or baryons over density, Jeans length, cooling timescale, etc. Comes with its own libraries. Runs on 10s-100s of processors.

Personnel:

J.-H. Choi - (lead, postdoc), Graduated and left UKY, 05/25/2021
I. Shlosman - PI (UK, faculty)
Dr. Yang Luo (PostDoc)

Julianne Goddard, Added to group, 05/25/2021

Funding:

Support: NSF, NASA/Astrophysics Theory Program


Physics of Galactic Outflows

This project deals with the feedback from stellar evolution (e.g.,
supernovae) and Active Galactic Nuclei (AGN). Especially during the early stage of galaxy formation stellar and AGN feedback trigger massive winds from galaxies. Understanding the physics of these winds is imperative to analyzing the high-redshift galaxies to be observed by the HST and the JWST telescopes. We use both FTM and GADGET codes to model these winds.

Personnel:

Dr. R. Sadoun - (lead, postdoc), Graduated and left UKY, 05/25/2021
Dr. E. Romano - Diaz (postdoc)
Dr. J.-H. Choi - (postdoc), Graduated and let UKY, 05/25/2021
Dr. I. Shlosman - PI(UK, faculty)
Dr. Yang Luo (PostDoc)

Funding:

Support: NSF, NASA/Astrophysics Theory Program



Instabilities in Stellar Bars of Disk Galaxies

This project deals with galactic dynamics of isolated disk galaxies embedded in dark matter halos. Such disks experience spontaneous symmetry-breaking and develop strong stellar bars. Such bars themselves are unstable to various vertical perturbations (buckling). Understanding these instabilities is imperative and involves chaotic (nonlinear) dynamics. We use both FTM and GADGET codes to model these instabilities.

Personnel:

Xingchen Li, Graduate, added 05/25/2021

Ms. Angela Collier (grad. student), Graduated and left UKY, 05/25/2021
Da Bi (grad. student)
Dr. C. Heller (faculty, Georgia SU)
Dr. I. Shlosman (UK, faculty)
Dr. Yang Luo (PostDoc)

Funding:

Space Telescope Science Institute

Publications:

2020

  1. Direct Collapse to Supermassive Black Hole Seeds: the Critical Conditions for Suppression of H2 Cooling,  Luo, Y., Shlosman, I., Nagamine, K., Fang, T.  MNRAS, 492, 4917 (2020)

2019

  1. Stellar Bars in Counter-Rotating Dark Matter Halos: Role of Halo Orbit Reversals, Collier, A.,  Shlosman, I.,   Heller, C.H. MNRAS, 489, 3102 (2019) 
  2. Dark Matter Bars in Spinning Halos, Collier, A., Shlosman, I., Heller, C.H. MNRAS, 488, 5788 (2019) 


2018

  1. Lyα Properties of Simulated Galaxies in Overdense Regions: Effects of Galactic Winds at z > 6, Sadoun, R., Romano-Diaz, E., Shlosman, I., Zheng, Z. MNRAS, 484,  4601 (2018)
  2. Direct Collapse to Supermassive Black Holes with Radiative Transfer: Cosmological Halos, Ardaneh, K., Luo, Y., Shlosman, I., Nagamine, K., Wise, J., Begelman, M. MNRAS, 479, 2277  (2018)
  3. Collapse to Supermassive Black Hole Seeds with Radiative Transfer: Isolated Halos, Luo, Y., Ardaneh, K.,  Shlosman, I., Nagamine, K., Wise, J., Begelman, M. MNRAS, 476, 3523 (2018)
  4. What Makes the Family of Barred Disk Galaxies So Rich: Damping Stellar Bars in Spinning Halos, Collier, A., Shlosman, I., Heller, C. MNRAS, 476, 1131 (2018)


2016

  1. The Direct Collapse to Supermassive Black Hole Seeds: Comparing AMR and SPH Approaches, Luo, Y., Nagamine, K., Shlosman, I. MNRAS, 459, 3217 (2016)
  2. The Baryon Cycle at High Redshifts: Effects of Galactic Winds on Galaxy Evolution in   Overdense and Average Regions, Sadoun, R., Shlosman, I., Choi, J.-H., Romano-Diaz, E. ApJ, 829, 71 (2016)
  3. Supermassive Black Hole Seed Formation at High Redshifts: Long-Term Evolution of the Direct Collapse, Shlosman, I., Choi, J.-H., Begelman, M., Nagamine, K. MNRAS, 456, 5000 (2016)
  4. AGN jet power and feedback controlled by Bondi accretion in brightest cluster galaxies, Fujita, Y., Kawakatu, Y., Shlosman, I. PASJ, 68, 26 (2016)
  5. The young radio lobe of 3C 84: inferred gas properties in the central 10 pc, Fujira, Y., Kawakatu, N., Shlosman, I., Ito, H. MNRAS, 455, 2289 (2016)
  6. Observational properties of simulated galaxies in overdense and average regions at redshifts z = 6-12, Yajima, H., Shlosman, I., Romano-diaz, E., Nagamine, K. MNRASm 451, 418 (2016)

2014

  1. S. Fujita, N. Kawakatu and I. Shlosman "AGN Jet Power and Feedback Controlled by Bondi Accretion in Brightest Cluster Galaxies,"Monthly Notices of Royal Astronomical Society, submitted (2014)
  2. E. Romano-Diaz, I. Shlosman, J.-H. Choi and R. Sadoun "The Growth of Galaxies at High Redshifts in Overdense Environments," Astrophysical Journal Letters, 790, in press (2014)
  3. S. Long, I. Shlosman and C. Heller "Secular Damping of Stellar Bars in Spinning Dark Matter Halos,"Astrophysical Journal Letters, 783, L18 (2014)

2013

  1. J.-H. Choi, I. Shlosman and M.C. Begelman "Supermassive Black Hole Formation at High Redshifts via Direct Collapse,"Astrophysical Journal, 774, 149 (2013)
  2. I.Shlosman "Secular Evolution of Galaxies" Proc. XXIII Canary Islands Winter School of Astrophysics on Secular Evolution of Galaxies, chapter 9, p. 555, J. Falcon-Barroso and J.H. Knapen (eds.), Cambridge Univ. Press (2013)


Grants

  1. Shlosman, Isaac HST-AR-12639.01-A The Corollaries of the Ultra-Compact Nuclear Rings in Disk Galaxies Space Telescope Science Institute 10/1/2011 - 9/30/2015 $99,179


  1. Ministry of Science and Education, Japan, PI (to Osaka University) on "Formation of Supermassive Black Hole Seeds at High Redshifts," (4/1/2014 - 3/31/2017)
  2. STScI (NASA)/Theory: PI on "The Corollaries of the Ultra-Compact Nuclear Rings in Disk Galaxies," (11/1/12-10/31/14)
  3. STScI (NASA)/GO), Co-I on "Unveiling the Structure of the Farthest Galaxy Protocluster: WFC3 Imaging of a z ~ 8 Galaxy Overdensity," (9/1/12-8/31/14)
  4. NSF: Co-I on "CC-NIE Integration: Advancing Science through Next Generation SDN Network (10/1/12 - 9/30/14), V. Kellen (PI), J. Griffioen (Co-PIs)


  1. Shlosman, Isaac HST-AR-12639.01-A The Corollaries of the Ultra-Compact Nuclear Rings in Disk Galaxies $79,344 Space Telescope Science Institute 10/1/2011 9/30/2014

Center for Computational Sciences