Commit 696aba5c authored by Laura Ketzer's avatar Laura Ketzer
Browse files

readme changes

parent 41ce80fc
......@@ -26,6 +26,9 @@ the density of the planet,
<a href="https://www.codecogs.com/eqnedit.php?latex=\small&space;\epsilon" target="_blank"><img src="https://latex.codecogs.com/gif.latex?\small&space;\epsilon" title="\small \epsilon" /></a>
is the efficiency of the atmospheric escape with a value between 0 and 1, and K is a factor representing the impact of Roche lobe overflow (Erkaev et al., 2007), which can take on values of 1 for no Roche lobe influence and <1 for planets filling significant fractions of their Roche lobes.
**Stellar high-energy evolution** <br>
Most previous studies of exoplanet evaporation approximate the stellar XUV evolution by using the average activity level of stars in a specific mass bin for well-studied clusters of different ages, and approximating it with a broken power-law with a $100$ Myr-long saturation regime. Observations and theoretical studies show, however, that stars spin down at a wider range of ages (see [^Barnes-03], [^Matt-et-al-12], [^Tu-et-al-20], Garaffo et al. 2015). In the context of exoplanet irradiation, this was explored in simulations by Tu et al. (2015) and Johnstone et al. (2015). Their studies show that the saturation timescales can range from $\sim10$ to $300 $Myr for solar-mass stars. Hence, a star that spins down quickly will follow a low-activity track, while a star that can maintain its rapid rotation will follow a high-activity track. This translates into significantly different irradiation levels for exoplanets, and thus the amount and strength of evaporation. Based on the findings by Tu et al. (2015), we generate a more realistic stellar activity evolution of the host star by adopting a simplified broken power-law model with varying saturation and spin-down time scales to approximate a low-, medium- and high-activity scenario for the host star. \vspace{0.5cm}
### Planet Model description: <br>
At the moment, the user can choose between two planet models.
......@@ -50,7 +53,12 @@ To be implemented...
(Tu et al., 2015 model tracks for the X-ray luminosity evolution,
Jackson et al., 2012 sample of X-ray measurements in young clusters)
* **example_V1298Tau**: evolve the four young V1298 Tau planets as shown in "X-ray irradiation and evaporation of the four young planets around V1298 Tau" (Poppenhaeger, Ketzer, Mallon 2020)
[Link to our paper: ](https://arxiv.org/abs/2005.10240)
* **example_V1298Tau**: evolve the four young V1298 Tau planets as shown in "X-ray irradiation and evaporation of the four young planets around V1298 Tau" [^Poppenhaeger-et-al-20]
* **population_evolution**: evolve a whole population of planets (to be fully implemented in the future)
[^Poppenhaeger-et-al-20]: [Poppenhaeger, Ketzer, Mallon 2020](https://arxiv.org/abs/2005.10240)
[^Tu-et-al-20]: [Tu et al. 2020](https://arxiv.org/abs/2005.10240)
[^Matt-et-al-12]: [Matt et al. 2012](https://arxiv.org/abs/1206.2354)
[^Barnes-03]: [Barnes 2003](https://arxiv.org/abs/astro-ph/0303631)
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