{%extends "base.html" %} {% block content %}

Contamination & Visibility Calculator


This tool is designed for the slitless observation modes of all JWST instruments. For slitless observations, the spectrum of a target star may be contaminated by partially overlapping spectra of nearby stars. For a given target, this contamination depends on the position angle (PA) at which the observations are taken. This tool simulates NIRISS SOSS, NIRCam Grism Time Series, and MIRI LRS observations of a given target, and produces an estimate of the level of contamination as a function of the PA of the observation, thus making it useful to plan observations at the optimal PA. The tool also computes the JWST accessibility windows of the target, along with the corresponding accessible PAs for the chosen instrument/observation mode.

Note: The field stars used for this analysis are retrieved from the 2MASS point source catalogue. Contamination from stars missing from the 2MASS PSC is thus not modelled; this may be important for faint targets.

{{ form.hidden_tag() }} {% include 'target_resolve.html' %}
R.A.
{{ form.ra(value=form.ra.data, size=10, rows=1, class='form-control') }}
Decimal Degrees
The right ascension of the target
Decl.
{{ form.dec(value=form.dec.data, size=10, rows=1, class='form-control') }}
Decimal Degrees
The declination of the target
{% for error in form.ra.errors %}

{{ error }}

{% endfor %} {% for error in form.dec.errors %}

{{ error }}

{% endfor %}

{{ form.mode_submit(id='modesubmit', style="visibility: hidden;") }}
{{ form.companion(value=form.companion.data, size=50, rows=1, class='form-control') }} RA offset ("), DEC offset ("), 2MASS J (mag), H (mag) and Ks (mag) [comma separated, no spaces]

{% for error in form.companion.errors %}

{{ error }}

{% endfor %}

PA Min
{{ form.pa_min(value=form.pa_min.data, size=10, rows=1, class='form-control') }}
Degrees
The lower limit on the position angle
PA Max
{{ form.pa_max(value=form.pa_max.data, size=10, placeholder="3 - 6", rows=1, class='form-control') }}
Degrees
The upper limit on the position angle
{% for error in form.pa_min.errors %}

{{ error }}

{% endfor %} {% for error in form.pa_max.errors %}

{{ error }}

{% endfor %}

{{ form.calculate_submit(class="btn btn-success") }} Calculate only the visibility of the target.


{{ form.calculate_contam_submit(disabled=form.calculate_contam_submit.disabled, class="btn btn-success") }} Calculate the visibility and the contamination. This can take up to 20 seconds! (Currently only available for SOSS mode)

{% endblock %}