Sky Surveys
Optical Surveys
SDSS
The Sloan Digital Sky Survey has created the most detailed three-dimensional maps of the Universe ever made, with deep multi-color images of one third of the sky, and spectra for more than three million astronomical objects. Learn and explore all phases and surveys—past, present, and future—of the SDSS.
It’s just 20 years old. See The first high-z quasar of SDSS was observed by Xiaohui Fan and Micheal Strauss on the Thanksgiving morning, 1998.
DES
The Dark Energy Survey (DES) is a visible and near-infrared survey that aims to probe the dynamics of the expansion of the Universe and the growth of large-scale structure. The survey uses the 4-meter Victor M. Blanco Telescope located at Cerro Tololo Inter-American Observatory (CTIO) in Chile. It uses g, r, i, z, and Y bands. DECam has one of the widest fields of view (2.2-degree diameter) available for ground-based optical and infrared imaging.
It can do: supernovae cosmology, BAO, galaxy cluster finder, weak lensing, etc.
I uses DECaLS (DECam Legacy Survey). Dustin Lang made a wonderful skyview map. Currently DES is only a photometric survey.
HSC
The Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) is led by the astronomical communities of Japan and Taiwan, and Princeton University. It’s a photometric survey for 1400 square degrees using Hyper Suprime-Cam mounted on 8.2m Subaru Telescope. It is now the seriously kicking-ass survey for galaxies and cosmology.
The main science goals contain: weak lensing cosmology, high-z galaxies, general galaxy formation and evolution (like stellar-halo connection), etc.
HSC data entrance: https://hscdata.mtk.nao.ac.jp/hsc_ssp/
SQL: https://hscdata.mtk.nao.ac.jp/datasearch/
Image cutout: https://hscdata.mtk.nao.ac.jp/das_quarry/dr2.1/
PSF model: https://hscdata.mtk.nao.ac.jp/psf/6/
SkyMap: https://hscdata.mtk.nao.ac.jp/hsc_ssp/dr2/s18a/hscMap
HSC Public DR2: https://hsc-release.mtk.nao.ac.jp/doc/
- Header:
ra
,dec
,layer
(such ass18a-wide
),z_spec
,z_phot
, etc. i-band
:image
image_header
hsc_mask
(This is the binary mask produced by HSC pipeline)hsc_mask_header
variance
variance_header
mask
(This is the mask used for ELLIPSE)ell_free
ell_fix
info
img_size
: size in pix, such as [1000, 1000]m10
orm100
bad_mask
: if the center of galaxy is obscured by maskmean_interval
: such as 20 kpc - 50 kpcmean_e
: mean ellipticity withinmean_interval
mean_pa
: mean PA withinmean_interval
global_bkg
: the background measured bysep
after masking out satellittesglobal_rms
: therms
measured bysep
mean_skyobj
: the mean value ofskyobj
within [1 arcmin, 3 arcmin] and 8.4 arcsec.
r-band
g-band
Dragonfly
- Canon 400mm f/2.8 IS II lens + SBIG STF-8300M CCD
- Aperture: D = 134 mm
- CCD: 3326 × 2504 pixels, 43% efficiency in R and G, 2.8”/pixel, 2.6 deg*1.9 deg FOV.
- Read noise: 10 electrons. Gain: 0.37 electrons/ADU.
- Dark noise: 0.04 electrons/s.
- Tracking error: rms = 1.5”.
Redshift surveys
Transient Surveys
Pan-STARRS
Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) is a well calibrated telescope for transient surveys.
IFU Surveys
MaNGA survey
The current data release is v2_1_2, containing ~2700 galaxies with redshift ranges from 0 to 0.15.
- MaNGA survey overview
- Marvin: a tool specifically designed to visualise and analyse MaNGA data.
- Summary information about MaNGA objects (
fits
file). You can search in this file whether your objects are contained in current MaNGA data release. You can also using SDSSnavigate
andexplore
tool to see whether your objects are contained in MaNGA. - MaNGA Pipe3D Value-Added-Catalogue by Sanchez et al. This is what I use in my research. This VAC catalog contains the physical properties and also information of gas emission lines. _Note: The SFR in this catalog is calculated by summing up H⍺ SFR of every spaxel in the FOV. So the genuine SFR must be larger. The IMF used here is Salpeter, while the most prevalent IMF is Kroupa IMF.
- MaNGA cube files, if you want to study the properties of specific galaxies.
SAMI survey
- SAMI survey overview
- SAMI objects list: can be opened with
.txt
using TOPCAT. - SAMI single object viewer: better GUI than MaNGA. After finding your objects in the SAMI objects list, you can just input the
CATID
, then related files can be downloaded. - SAMI data query using SQL