Seminar 2. Viewing galaxies in 2D

• Title: Viewing Galaxies in 2D
• Subtitle: Spatially-resolved kinematics and stellar populations with IFS

Spectroscopy

We have incoming light which passes through a slit and then a grating and splits it in different wavelengths. Then the detector detects the continuous electromagnetic spectrum.

• But if we put a cold glass before the slit, we will have an absorption spectrum.
• If we put a cold glass before the slit, we will have an emission spectrum.

What will happen if we point our telescope at a galaxy?

• We will have some emission lines in the spectra.

Now, this depends on the slit and how you place it. If you let a lot of points go through, you're getting information from a big region.

Integral field spectroscopy

• Used first at 1789. But it wasn't until ~2000 that it was largely used.

@TODO: Fill

Integral field units

• Lenslet array
• Fibre array
• Image slicer
• Micro-slicer

Optimal performance: slicer (anyways, none of them is the best, each of them has advantages and disadvantages)

Uses of IFUs

• Earth remote sensing
• Weather forecasting
• Monitoring natural disasters and climate change

• Resolved stellar populations (stars, HII regions, planetary nebulae, galactic star formation)
• Extended objects (extragalactic): stellar and gas kinematics, stellar populations, gas content
• Crowded regions: distances of different galaxies at once; deblend AGN from hast galaxy emission
• Distant universe: properties of galaxies at z~2, lensed galaxies, measure many redshifts at once

Galaxy evolution with IFS

@Note: I stopped taking notes because the seminar was very interesting and I didn't have time to write everything down.