1. Asteroseismic Modeling Portal (AMP) Development
Haiying Xu, Travis Metcalfe (PI)
NCAR, Space Science Institute

2. Asteroseismology
Asteroseismology is a powerful technique to determine the ages and other properties of field stars.
Ricker et al. (2014)

3. Echelle diagram for star KIC 8379927
Echelle diagrams for typical examples of the star type KIC The plot shows the match to the frequencies after the scaled solar surface correction of CD has been applied to the raw model frequencies
Different symbols are used to indicate the radial, dipole and quadrupole and octupole oscillation modes.

4. H-R diagram for star KIC 8379927
Spectroscopic H-R diagram for the star type KIC Solar –composition evolution tracks from ASTEC for masses between 0.75 and 1.75 Mass in solar units are shown as dotted lines.
H-R means Hertzsprung-Russell
Y axis is optimal luminosity (in solar units)
X axis is optimal effective temperature

5. Precise stellar properties
42 selected for seismology (blue), 34 selected for exoplanets (red)
Some disagreement for most massive and youngest (F-like) stars
Fitting frequencies improves precision of properties by 2 times or better
Comparison of the asteroseismic radii, masses and ages derived from grid-modeling (GM, Chaplin) with the AMP, including the simple (black), F-like(red) and mixed-mode starts. It compares the values and uncertainties.
Chaplin et al: 2.1% radius, 5.5% mass, 20% age
AMP precision: 1.2% radius, 2.8% mass, 8% age
Huber et al: 2.2% radius, 6.0% mass, 28% age
AMP precision: 1.0% radius, 2.6% mass, 13% age
Metcalfe et al. (2014); Silva Aguirre et al. (in prep)

6. Asteroseismic Modeling Portal
A parallel genetic algrorithm
Aarhus stellar evolution code
Adiabatic pulsation code
ASTEC-the Aarhus Stellar Evolution Code
ADIPLS- the Aarhus adiabatic oscillation package
MPIKAIA- Stellar Structure Modeling using a parallel Genetic Algorithm for Objective Global Optimization
The Asteroseismic Modeling Portal is a web-based interface to the stellar model-fitting pipeline.
The underlying science code uses a parallel genetic algorithm on XSEDE supercomputing resources to optimize the match between asteroseismic models produced by the Aarhus stellar evolution code and adiabatic pulsation code and a given set of observational constraints.

7. Asteroseismology – Forward Model
Start with a forward stellar simulator: the Aarhus Stellar Evolution Code (ASTEC)
Stellar
Parameters
Forward Simulation
Observables
M/M⊙
Mass Z
Initial heavy element mass fraction Y
Initial helium mass fraction α
Mixing-length (convective efficiency) τ
Stellar age
Direct ASTEC model evaluation. In a direct model run, a scientist specifies a star’s parameters, and a model is generated using ASTEC. Data about the hypothetical star, including Echelle and HR diagram are procuded for inspection.

8. Asteroseismology – Genetic Algorithm
Find a model that fits the observations
Computationally cost
Forward Simulation
Stellar
Parameters
Observables
Create population
of candidate stars
Choose best stars
Adjust population
Model
Model-Fitting Genetic Algorithm
(Properties from Observations)
Asteroseimology allows astronomers to determine the properties of sun-like stars by analysis of their oscillation periods
Observable parameter optimization. In an optimization run, a scientist specifies observable properties, such as
Pulsation frequencies and a genetic algorithm is used to identify the stellar model that best fits the observed data.
System GA
SUs
Frost (BG/L)
23,231
Kraken
16356
Big Red
38,194
Stampede
9,659
Lonestar
22,858

9. AMP Portal workflow AMP workflow Moved to Aarhus in 2013 Frost Kraken
Users interact with a web server
Grid processing on a daemon server
Only communication through a SQL database
Web interface attribute preparation
Where a user logs in, record the authentication instant, IP
When a simulation is submitted, associate with the authentication record
Append-only DB tables and backup log files
Gridamp daemon attribute processing
When processing a job, the recorded authentication instant is tied with it
Cache the generated certificate(lifetime limited by the community account certificate lifetime)
Every simulation uses the same community account certificate proxy
Gridamp accounting data retrieval
Uses returned grid job id to get job status information
Gateway Interface DB
GridAMP Daemon
Stampede
Grid
Resources
Virtual Servers

10. Input Parameter Interface

11. Results page

12. Results page (cont’d)

13. Results page (cont’d)

14. Results page (cont’d)

15. Results page (cont’d)

16. Results page (cont’d)

17. A successful portal for 8 years
Since 2007, NCAR developed and maintained AMP.
Developed by Matthew
110 astronomers, 18,795,892 SUs and jobs
Stampede
Kraken
AMP
Frost
2007
2008
2009
2010
2011
2012
2013
2014
2015
GT 4
GT 5
GT 6

18. Relocation and Upgrade
Recently activities:
In FY2013, virtual server relocated from NCAR to Aarhus, Denmark
In FY2014, resources changed from Kraken to Stampede
In FY2015, OS and software upgrade
Recently activities:
In FY2013, NCAR worked closely with system admins at Aarhus Univ at Denmark to move the servers of AMP from NCAR to Aarhus University.
In FY2014, NCAR worked with TACC staffs to change the computing resources from Kraken to Stampede
In FY2015, NCAR replaced the virtual server GridAMP daemon with a new OS, and upgraded GRAM, openssl, and myproxy etc.

19. Future Replace GRAM Optimize the scientific codes by TACC staff
Upgrade more servers
Replace GRAM with Gsissh for job submission
Optimize the scientific codes to make best use of the computing resources
Change the current OS of web server and database server to a newer one