IFS ETC v1.3.4 About

Lazuli IFS Spectroscopy

The Lazuli Integral Field Spectrograph ETC

IFS exposure-time calculator for stellar, SN Ia, and custom spectra across the selected wavelength range. Transiting-planet hosts have their own page: Transit spectroscopy.

Mode

Requested SNR is an input. Exposure time and detector ramp settings are computed.

Source

Temperature (K)

log g

[Fe/H]

PHOENIX model grid shipped with lazuli_exo: 2000–12000 K, log g 3.5–5.5, solar metallicity. T_eff / log g outside the grid are clamped and a non-zero [Fe/H] uses the solar model (noted in the result).

CalSpec star

SN Ia redshift (z)

SN Ia color (c)

SN Ia stretch (x1)

Temperature (K)

Flat spectrum

Alpha (Fλ ∝ λ^α)

Reference wavelength (A)

Custom spectrum (.csv, .txt, .dat)

Two columns with no header: wavelength in A and flux in FLAM. Comma-separated (e.g. 3500.23,1.366e-16) or whitespace-separated (e.g. 3500.23 1.366e-16) are both accepted. Lines beginning with # are ignored. Leave the normalization magnitude blank to use the file's absolute FLAM flux, or set it to rescale the spectrum to that brightness. Custom uploads are used for this request only.

Transiting planet host? The Transit spectroscopy page simulates the transmission spectrum with its own readout.

Magnitude (AB or Vega)

Magnitude bandpass

Magnitude system

slicersim works in AB; a Vega magnitude is converted with the band's AB−Vega offset.

Background

Zodiacal background (V-band AB mag/arcsec²)

Surface brightness of the sky background. Smaller = brighter sky. Default 22.5 (~20° from the ecliptic).

Instrument

Spectrograph field

Instrument configuration

CBE is the current throughput and noise budget; EOL is the degraded end-of-mission case.

Frame readout

Jitter (mas)

Requested SNR

SNR unit

A resolution element spans 2.3 px (CBE) or 2.5 px (EOL). The requested, reported and plotted SNR all use the selected unit.

Wavelength min (nm)

Wavelength max (nm)

Result

No results yet. Select inputs and click Calculate.

Configuration Summary

Source type

PHOENIX model

Source

109vir

Flux scaling

24.0 AB

Bandpass

Bessell V

Spectrograph

wide

Configuration

CBE

Readout

Full frame (2.83 s)

Wavelength range

800-1200 nm

Jitter

10 mas

ETC version

slicersim v1.3.4

Git commit

repository

Plots

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Input fields & detector

Narrow (0.04″/spaxel) and wide (0.08″/spaxel) input fields as on the sky, and their 2D slices projected onto the detector through slicersim's spot mapping.

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Up-the-ramp visualizer

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