Questions tagged [modeling]
The modeling tag has no usage guidance.
13
questions
6
votes
1answer
77 views
Why does the convective core in an intermediate to high mass star shrink?
The image below shows the evolution of the hydrogen mass fraction profile for a 5 solar mass star in the main sequence. I would expect that the size of the convective core stays roughly constant as ...
2
votes
2answers
117 views
Estimate prevalence of ʻOumuamua-style interstellar obects inside Jupiter orbit now that C/2019 Q4 (Borisov) is found?
Now we know two of them, so maybe it's not an outlier.
We have two points so we can draw a line. How many similar macroscopic objects should be zipping through space at ~30 km/sec so that we would ...
4
votes
1answer
38 views
How to model and subtract nebular emission lines from stellar spectrum
I have optical stellar spectra from a star forming region with spatially varying nebular background.
I want to subtract the nebular lines from the stellar spectra (which are varying in intensity from ...
3
votes
1answer
68 views
Brown Dwarf Cloud Models
There has been research that suggests that the changing brightness of Brown Dwarves are due to bands of Iron/Silicate clouds. Several models have been made that supports that hypothesis. My question ...
1
vote
0answers
16 views
Brown dwarf cloud models [duplicate]
There has been research that suggests that the changing brightness of Brown Dwarves are due to bands of Iron/Silicate clouds. Several models have been made that supports that hypothesis. My question ...
1
vote
1answer
76 views
Dynamical modelling of galaxies with counter-rotating components using the Schwarzschild method
I am currently trying to understand dynamical modelling using Schwarzschild's method. I have been doing some reading the past days, but I suspect that I am getting something really wrong. According to ...
23
votes
1answer
2k views
When will the number of stars be a maximum?
There are very roughly a "mole" of stars in the universe. Wikipedia quotes an estimate of $3 \times 10^{23}$ though the number is associated with some debate and uncertainly.
I'd like to know if ...
1
vote
0answers
17 views
Clarity on dust extinction terms and implementation: R_V, A_V, and E(B-V)
I have created a model galaxy spectrum using STARBURST99 and want to compare it to an observed spectrum of a particular galaxy. I understand that I need to redden ...
3
votes
0answers
77 views
What is the actual visual characteristics of a black hole?
Is there a safe distance in which a black hole can be observed with the human eye? What is a safe distance?
I have seen many computer simulated and artist renditions, and I am not sure if they ...
1
vote
0answers
36 views
How do you fit a model SED to an observed galaxy spectrum with photometric data?
I have a spectrum of a galaxy from HST data and SDSS data (resulting in a nearly continuous SED from the FUV~1000 Angstroms through infrared). I have created a model SED with the galaxy simulation ...
0
votes
1answer
103 views
What is the lyman-werner background?
I've seen several papers that discuss the Lyman-Werner Background (LWB) when modeling star and galaxy formation in the early universe. One in particular (https://arxiv.org/abs/1803.04527) even varies ...
2
votes
2answers
96 views
Has stellar evolution ever been modeled analytically?
I'll still remember the handout my astronomy professor gave us more than several decades ago; Our Friends the Polytropes. We spent a lot of time learning how polytropes, simple analytical power-law ...
4
votes
1answer
73 views
Why does the precession of the earth affect other planets?
In the Wikipedia article on numerical integration of planetary motion it states:
...the flattening of the Earth causes precession, which causes the
axial tilt to change, which affects the long-...
