TIPS/JIM August 18, 2011

TIPS/JIM August 18, 2011 Agenda: INS Division News (Margaret Meixner) Please Help Me! An Intro to the new HST Help Desk (Jennifer Mack)! Signal to noise capabilities of COS if need be (Derck Massa)! Next TIPS/JIM: September 15, 2011

INS News Astro-statistics course: Sept-October, August 26, deadine for signup Keswick building lease has been signed; Lennon is on housing committee; current thinking are moves to occur summer 2012 to fall 2012 In vacation season & Appraisal writing season Not to early to think about what you might New INS arrivals: Janice Lee, Fall 2011, working with WFC3 team John Debes, will start Monday August 29, on COS/STIS team Departures from INS: Parviz Ghavamin moved onto Towson University Faculty Keith Noll, will depart in Fall 2011 Job advertisements in INS: RIA positions are advertised: see Aparna or Max COS visiting Scientist position: See Ale

Please Help Me! An Intro to the new Help Desk TIPS: Aug 18, 2011 J. Mack

2011 STScI TransiCon > Remedy (1990 s) to Footprints 4 Workspaces Help, Support, Archive, OPO Organized via unique incoming email address Separates different STScI encces Operates independently of other workspaces A composite of Cckets, contacts, knowledge bases, preferences Help@STScI TransiCon on June 15 th, 2011 Support for Cycle 19 Phase II

Purpose: Support the HST (and JWST) User Community Importance of this Role: Item #1 from the Director s Office Principles for STScI The InsCtute was set up to provide long term guidance and support for the sciencfic effort, provide a mechanism for engaging the parccipacon of astronomers throughout the world, & provide a means for the disseminacon and uclizacon of the data Access: Email help@stsci.edu Web interface haps://footprints.stsci.edu

Help ConfiguraCon and TesCng CollaboraCon across Divisions (INS, OED, SMO, ITSD) CollaboraCon across Missions (HST, JWST) Help Workspace Supports 14 teams Triage level: Help AcCve Instruments: ACS, COS, STIS, WFC3 InacCve Instruments: FOS, GHRS, NICMOS, WFPC2 Phase I/II support: APT, ETC, SMO Soeware: SSB Upcoming: JWST

Footprints Features Web based; Plahorm independent; Aaachments allowed HST ProPer database populates user fields (Title, AffiliaCon, HST proposal IDs) Auto nocficacons (New or InacCve calls) EscalaCons enable the automacon of business Auto generated reports (Triage= weekly, Team= monthly) Emailed to teams for tracking development needs via call categories (i.e. soeware, documents, tools) Searchable Knowledge base (Public vs. internal) Repository for known issues, procedures, solucons Allows Cmely info and FAQs to be conveyed to users

New Procedures GOAL: SoluCon: Develop expercse within the RIAB Provide mentoring, encourage learning process Minimize reliance on support from IS s New roles: Agent, Advisor, Expert No more weekly duty shies On arrival of new ticket, all agents are notified Individuals select tickets based on expertise or interest GOAL: SoluCon: Communicate user queries with Teams Provide call category stats for enhancements Give credit for the excellent work RIAs do supporcng users Monthly reports distributed to teams Calls accessible to non agents via read only accounts

User Support Roles Agents: RIAs trained to service Cckets via Footprints Advisors: Expert level RIA/RIS Oversee team accvices Provide guidance to agents Experts: IS/CS in team Replies to agent or Replies directly to the user (cc: help)

EscalaCon Rules Enable the automacon of processes In effect Mon Fri (9 am 5 pm) Triage : Goal route calls within 2 hours Team : Goal first response to user within 1 day Auto nocficacon emails all agents: When NEW call arrives When no one has taken the call aeer 1 day Auto nocficacon emails assignee: When call is IN PROGRESS and INACTIVE for 2 days When call is on HOLD and INACTIVE for 10 days (2 weeks) Auto nocficacon emails supervisor : When team has not responded to call aeer 1 day When call is IN PROGRESS but INACTIVE for 3 days

ReporCng Calls by Team: (158 Cckets June 15 Aug 3) Count Team

Team Report

Read only Accounts for INS Teams Purpose: For IS, CS, or PC Enables team to view call resolucon Provides call details for soeware/doc enhancements Access: Read only Can view all Cckets (i.e. ACS Team Calls) Can run reports (Tickets by category, by agent, etc) User ID s: awt_help cos_scs_help wfc3_help Passwords: (To be emailed to each team)

QuesCons? Policy & Oversight (RIAB) Jennifer Mack (mack@stsci.edu) Max Mutchler (mutchler@stsci.edu) AdministraCon & Training Needs Abhijith Rajan (arajan@stsci.edu) Brian York (york@stsci.edu)

COS signal to noise capabilities Limitation of COS S/N No good 2-D flat available. Fixed pattern noise dominates COS spectra. An uncalibrated COS spectrum is affected by: Optical response Smooth Fixed in wavelength space (sort of) Fixed pattern noise Due to detector irregularities Rapidly varying with detector position Fixed in detector space Separating fixed pattern noise and spectrum: Iterative approach Direct approach

The FP-POS Algorithm Data taken at several, slightly shifted wavelengths 1. Align all of the spectra in space and create a mean spectrum (reduces fixed pattern noise by 1/ N). 2. Divide each spectrum by the mean and average the results in detector space for an estimate of the fixed pattern noise. 3. Divide each spectrum by the fixed pattern noise estimate. 4. GOTO 1 and iterate until done. Some limitations: Algorithm can get confused by busy spectra. COS FP-POS offsets are nearly identical, so some spatial frequencies are poorly constrained. Works well in many cases, but error estimates are a bit sketchy.

A 1-D flat derived by the FP-POS algorithm, as implemented by Tom Ake for COS. Grid wire shadows are marked.

(Left) Net spectrum of WD0308-565 from FP- Split algorithm, binned by 3 pixels (half a RESOL). Also shown: 3 weak S II IS lines, and a quadratic fit to 1220 < < 1250 Å. (Upper right) Poisson S/N in each bin. Features are spectral lines or grid wires. (Right) Normalized S II spectrum showing how well weak lines can be identified.

The Direct Approach To determine limiting S/N, need good error estimates for the fixed pattern template. 1. Uncalibrated standard stars typically have simple continua, whose line free regions can be represented by polynomials. 2. Align all spectra in wavelength space and fit them with one polynomial. 3. Divide each spectrum by the fit and average the results in detector space to get the fixed pattern noise. 4. No iteration needed. 5. Template errors follow from simple propagation of errors. Some limitations: Only works for sources with simple continua. Agrees well with templates from iterative approach.

Examples of polynomial fits Examples of fits to 4 FPPOS NET spectra from program 12086. Regions containing stellar lines (other than Ly ), IS lines and grid wire shadows have been eliminated. These high S/N data show how well polynomials fit the NET spectra.

Comparison of iterative and direct flats. Ratios of the NET spectra (black) and templates (red) -- both smoothed by 64 points to highlight systematic differences. Blue curve is the average of the two ratios.

Portions of a 1-D flat showing ±1 errors. Data are binned over 3 pixels, half a RESOL, and grid wire shadows are marked.

Histograms characterizing fixed pattern noise in each grating/detector. Plots show the dispersion about the mean of the fixed pattern templates including the grid wires (black), without grid wires (red) and expected Poisson errors (blue).

The Bottom Line for Standard Processing RMS S/N over the regions 1300 < x < 152000 for FUVA and 1000 < x < 145000 -- corrected for Poisson noise. G130M G160M FUVA FUVB FUVA FUVB RMS S/N 17.9 23.8 14.9 20.4 Max S/N 35.7 47.6 29.9 40.8 G130M is better than G160M because it s fatter. FUVB is better than FUVA because it is. To improve, a full 1-D flat is needed. A S/N = 50 template limits overall S/N to 100.

Effect of SN FF on exposure times