session 1 - working with hst data

Working with HST data

Mehdi Bozzo-Rey (mehdi@exploresciences.com), october 2015

Where to find ideas ?● Astronomy picture of the day● NASA, Hubble section● NASA, hubblesite.org● ESA, spacetelescope.org● Wikipedia

○ galaxy○ planetary nebula○ astronomy portal

● Twitter, lots of people to follow: NASA, ESA, ESO, big labs in the US, CERN etc …

● News.Ex: The Atlantic● Radio: CBC

Astronomy Picture of the day

NASA, Hubble section

NASA, Hubblesite.org

ESA, spacetelescope.org

Wikipedia, galaxy

Wikipedia, planetary nebula

Wikipedia, astronomy portal

News - ex: the atlantic

twitter

Radio : CBC

Where to get the data from ?

● Hubble Legacy Archive● MAST

HLA- search interface● Simple interface: simple but maybe too simple ?

HLA : the most important thing : help !

HLA help center : FAQ

HLA search - Inventory tab

HLA search - Images tab

HLA search - Interactive display

HLA search - Footprint tab

HLA - advanced search interface

HLA - Advanced Search - Data Products

Data Products : what are these things ?

From the help center:

What are the data product levels? What does "Best Available" mean?There are several levels of data in the HLA:

● Level 1 data are the individual exposures, projected ("drizzled") onto a common frame for each visit.● Level 2 data are the combined images (exposures with the same filter, same camera, and within the same visit).● Level 3 images are deep combined images or mosaics creating by combining data taken in different visits to the target.● Level 4 data are false color images (a combination of two or three colors, depending on what is available). They are

included with other selections to help users assess data quality.● Level 5 data are the community-contributed high-level science products (HLSP).● Level 0 (calibrated, unprocessed) are not available for direct searches but may often by found using the More... link.

Instruments overview

Instruments details

HST - list of filters● WFPC2 optical filters● WFC3 filters

Why does that matter ?

Astronomy cameras don’t take pictures in color. They combine 3 (Red, Green, Blue - RGB) or 4 (Luminance, Red, Green, Blue - LRGB) black and white pictures taken with one specific filter to make one color picture

wikipedia - visible spectrum

Filters … filters ...filters● Why so many filters then ?

○ Specific filters can be used to see a specific process

Sun - SOHO. Credit NASA Sun, Hydrogen Alpha filter