Output files
======================

This document aims to provide a detailed explanation of the output file generated by the gulls microlensing simulation. The output file contains a comprehensive set of data for each microlensing event, organized in columns. Below is a description of the column contents and their significance.

Column Structure
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The output file is structured into multiple sections, divided by the pipe symbol ("|"). Each section contains information related to different aspects of the microlensing event. The sections include field and coordinate information, source star properties, lens star properties, microlensing event properties, and more.

- **Field and Coordinate Information**: This includes the event's index, subrun number, field, galactic coordinates (l, b), and right ascension and declination (ra, dec).

- **Source Star Properties**: Details about the source star, such as its ID, distance (Ds), radius (Rs), proper motion (smu_l, smu_b), age, class (scl), and type (styp).

- **Lens Star Properties**: Information on the lens star, including its ID, distance (Dl), mass (Ml), proper motion (lmu_l, lmu_b), age, class (lcl), type (ltyp), bolometric magnitude (lMbol), effective temperature (lTeff), surface gravity (Llogg), and radius (Rl).

- **Microlensing Event Properties**: Parameters such as the impact parameter (u0), event angle (alpha), time of maximum magnification (t0), Einstein crossing time (tE), Einstein radius (rE), theta_E (thE), parallax effect (piE), source radius in Einstein radii (rhos), relative proper motion (murel), transverse velocity (vt), and shear (gamma).

- **Planet Properties**: For simulations involving planets, this section lists the planet's mass (Mp), semi-major axis (a), inclination (inc), orbital phase (phase), mass ratio to the host star (q), separation (s), and orbital period (period).

- **Weight and Flags**: Includes the raw weight (raww), final weight (w), and flags indicating certain conditions of the simulation (e.g., FSflag, flatsatFlag).

- **Magnitudes**: The magnitudes of the source and lens in various filters (e.g., J, F087, H, W149, W169).

- **Blending Flux (fs)**: The blending parameter, which is crucial for determining the combined flux from the source, lens, and any additional blended light.

- **Analysis Flags and Chi-square Values**: Indicators for the analysis status, including flat lightcurve flag (flatchi2), chi-square values for different fits (chi2_0, chi2_1, chi2), and the normalization weight (normw).

Interpreting the Data
---------------------

Each line in the output file represents a single microlensing event. The values are presented in a fixed-column format, with each column holding specific information about the event, as described above. To interpret the data:

1. Identify the event's properties by reading the corresponding columns based on the structure outlined.
2. Use the planet properties section to assess the characteristics of any involved planet.
3. The final weight (w) should be used for statistical analyses, such as creating histograms of event frequencies against certain parameters (e.g., planet mass).

It's essential to consider the flags and chi-square values for a comprehensive understanding of each event's quality and the simulation's overall fidelity.