Marco Feroci7th AGILE WorkshopINAF/IASF Rome Monitoring the Hard X-ray Sky with SuperAGILE Marco Feroci (INAF/IASF Rome) on behalf of the SuperAGILE Team

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Outline Experiment Overview In-flight Performance Overview of Scientific Results from SuperAGILE: Wide Field Imaging Long-term Monitoring of Bright Galactic Sources Short Transients Gamma Ray Bursts Go deeper: SA observations of GX Most of this talk to appear on Astronomy & Astrophysics : Feroci et al. 2009

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop AGILE mission – SuperAGILE experiment AGILE launched April 23, 2007 LEO orbit (550 km) 2.5° inclination Gamma (30 MeV – 50 GeV) + Hard X-ray instruments long pointings program SuperAGILE 4 x 1D coded mask imagers 6 arcmin angular resolution 18 – 60 keV energy band  15 mCrab 1 day sens. (5σ, on-axis) 2 us timing accuracy

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop SuperAGILE is a 2 x 1-D coded aperture resource-effective imager, devoted to image bright hard X-ray transients. The field of view is composed of two crossing regions of 107°x68°. Angular resolution is 6 arcmin (1D, both directions). IASF Roma 68°2 x 1-D 1-D 107° SuperAGILE in figures

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop SuperAGILE Imaging Z coding detectors X coding detectors Coded Direction Non-Coded Direction AGILE Pointing (in)Stability SA PSF & SA 1D Imaging: Making a liability an asset... 1° SA PSLA SuperAGILE data analysis is made very complex by the combination between the large attitude variation and the one-dimensional imaging. Attitude correction and Blind search of sources is done in a 2D space, but with 1D sensitivity. Computing time is critical.

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop A more complex field: 30 degrees from Galactic Center X coding detectorsZ coding detectors SuperAGILE Imaging

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop SuperAGILE PSLA & Sensitivity AGILE Attitude Post-facto Reconstruction: 1 arcmin In-flight Point Source Location Accuracy 90%: 1.5 arcmin In-flight 50 ks Sensitivity

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop SA Automated Orbital Analysis Normalized Counts for Crab Nebula: 0.15 cts cm -2 s -1 SA data are automatically processed after every contact of the spacecraft wih the Malindi ground station. 1D Images are integrated over the whole orbit, to obtain an unbiased picture of the sky. Sources are blind-searched for and identified, independently in both coordinates. Orbital source counts are normalized using the net exposure time and effective area for each detected source. Similar data processing is performed also on daily timescale.

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop 2-year GRID exposure

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop 2-year SA exposure

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Pittori et al., 2009 SuperAGILE Preliminary X-ray sources

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop SuperAGILE: detected sources This is NOT yet A CATALOG ! a. Non-uniform analysis of SA Data Archive (different SW versions for different epochs) b. Scientific Imaging SW not yet optimized c. S/N ratio for sources not optimized (Earth occultation not yet excluded in the image integration) c. Integration times typically limited to ~40 ks exposure or shorter (  mCrab limiting sensitivity)

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop SA detected sources: 0 th Order Statistics  60 sources, of which: 34 LMXB (56%) 19 HMXB (31%) 4 AGN (6%) 3 SGRs/AXPs 1 PWN With a Flux cut at 15 mCrab: ISGRI (Bird et al. 2007):  50 sources (57% LMXB, 38% HMXB) BAT (Tueller et al. 2009):  40 sources (59% LMXB, 31% HMXB) Despite the large non-uniformity of analysis and expsoure, source variability, …. SA sources  consistent with flux-limited LogN-LogS of persistent hard X-ray sources

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Simultaneous Wide Field Imaging

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop A Case Study: The Vela Field - Image Angular separation: Vela X-1 – GX ° GX – LMC X-4 39° Cen X-3 – Vela X-1 29°

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Vela Field: Light Curves & Pulse Profiles

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Long-Term Monitoring of Bright Galactic Sources

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop 44 days 45 days 20 days 51 days Del Monte et al. Submitted to A&A 2 Nov Dec 2008 SuperAGILE (20 – 50 keV) RXTE/ASM (2 – 12 keV) 160 days,  6.1 x 10 6 s Cyg X-1 in hard state

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop GRS during a radio flare (Trushkin S. et al., ATel #1509) (J.C.A. Miller-Jones, 2007) Historical radio mapping Radio monitoring

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop April 2008 Giant radio flare of Cygnus X-3 detected by RATAN-600 radio telescope Radio flux increasing of a factor ~10 3, from ~10 mJy to ~10 Jy S.A.Trushkin et al., ATel # Jy is typical flux for plasmoids emission ! Cygnus X-3 during a giant radio flare! In the same period SuperAGILE revealed a sudden increase in the hard X-ray emission See Talk by A. Chen to hear the rest of the story

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Continuous vs Sparse Monitoring 300 mCrab 2.4 Crab Swift/BAT

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Long-term Monitoring of Sco X-1 8 Crabs 100 s 2 Crabs

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Sco X-1: orbit history Time (bin 100s) SA Coordinate (bin 3 arcmin) Counts AC-induced Deadtime due to Transit through SAA Earth Occultation

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Rapid Flares from Sco X-1 SuperAGILE Raw Count Rates 200s 50s SAS 3 – 1-19 keV

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop The SuperAGILE Public Light Curves

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop The SuperAGILE Public Light Curves Results of the automated orbital analysis are immediately and automatically made public through the web page on the ASDC web site.

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Data products currently publicly distributed on the ASDC web site are the result of the automated analysis on orbital timescale only. The net sources integration time is typically 3 ks and only positive detections are included: upward bias on the flux ! Event files are not filtered for source visibility (wrt Earth occultation): bkg Poisson fluctuations up to 1.4 times higher: lower significance than best case. Fluxes are however normalized to the net source exposure. Source detections are included when the source is detected with at least 20% of the effective area. Unusual flux/source measurements are human-screened for validation before immission into the web page. Data analysis SW used in runtime not yet optimal. The SA Public Light Curves: CAVEATS

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Short X-ray Transients

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop AGILE Fast Reactions (May ‘09) 39 Astronomers’ Telegrams (ATel): 27 on Gamma-ray Transients 12 on X-ray Transients 37 GRB Coordinate Network (GCN) Telegrams: 21 on Gamma Ray Bursts (16 SA) 4 on Magnetars 12 with InterPlanetary Network (IPN) One fast communication every ~10 days

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop SAX J : day timescale Sudden outburst of the X-ray Transient SAX J (Pacciani et al., ATel #1428) 4U AX J Sco X-1 4U GX 17+2 ~1 day

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop IGR J : minute timescale Confirmed by later observations (ATels# : 1459, 1460, 1461, 1468) IGR J /XTE J is an X-ray Burster ! ATel #1445 (Del Monte et al.) – 27 Mar 2008 SuperAGILE detection of the first known type-I X-ray burst

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop SGR SGR Unfavorable pointing strategy. Marginal cooperation from the sources … Only a few detections. Examples : 5-10 ms time bin Soft Gamma Repeaters: tenths of seconds

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop The Galactic Center

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Yesterday in the Galactic Center SKYBIN SKYCOORD DIRECTION ZONE RATE ERR_RATE CTS cm-2 s-1 EXPOSURE NAME SIGN X Sco X X U X GX X GX X GX X GRS X Ginga X OAO X GRS X SWIFT J X U X GX X M One-day automatic integration on the GC: 13 sources from 38 mCrab to 3 Crab,

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Ginga U GX 17+2 GRS Sco X-1 GX 1+4 GRS GX 17+2 Ginga GX 1+4 4U Postcards from Galactic Center 4U Ginga Sco X-1 GX U AX J GX 5-1 Ginga U Ginga U GX 17+2 GRS Sco X-1 Daily variability in the Galactic Center (counts image)

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Not Always Detections … (but see Talk by A. Chen)

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop 37 Cygnus Region Persistent Emission (1.20 ± 0.07) × cm -2 s -1 at 23,4 σσ Position: (l,b) = (78.37, 2.04)°, error ~ 0.12° 1-day flare on April 27-28, 2008 [ATel #1492] » (2.9 ± 0.8) × 10-6 cm-2 s-1 at 3.7 σ » Position: (l,b) = (78.1, 2.0)°, error ~ 0.8° 1-day flare on June 20-21, 2008 [ATel #1585] » (2.5 ± 0.7) × cm -2 s -1 at 4.9 σ » Position (l,b) = (78.6, 1.6)°, error ~ 0.7° 1-day flare on November 16-17, 2008 [ATel #1848] » (2.5 ± 0.7) × cm -2 s -1 at 4.8 σ » Position (l,b) = (78.6, 2.1)°, error ~ 0.7° Gamma association: 3EG J FGL J Variable Sources in the Galactic Plane: e.g., 1AGL J

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop 38 The variable gamma-ray sources are very bright (  Crab). SuperAGILE simultaneous observation: upper limits between 10 and 40 mCrab. Weak and steady hard X-ray source in Swift/BAT survey. L  /Lx » 1 Interpretation models based on leptonic jet emission from Microquasars predict large emission at X-rays, so they are excluded by the simultaneous SuperAGILE upper limits. Variable Sources in the Galactic Plane: a possible interpretation Romero & Vila (2009) propose interpretation in terms of emission from hadronic jets in Galactic microquasars. This model is able to reproduce a Spectral Energy Distribution (SED) where the luminosity at X-rays is very small, consistent with the AGILE observations.

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Gamma Ray Bursts (but see Talk by E. Moretti)

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Ettore Del Monte, INAF IASF Roma ● 29 GRBs localized by SuperAGILE (18 in 2x1-D and 11 in 1-D) since July 2007 => ~1 GRB/month ● 3 arcmin radius uncertainty on the localization and minimum detected fluence of ~5x10 -7 erg cm -2 ● 1 – 2 GRBs/month detected by SuperAGILE outside the FoV (input to Interplanetary Network) SA & Gamma Ray Bursts

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Individual Pulsations from Vela X-1 (P=283s) GRB SA & Gamma Ray Bursts

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Time GRB090516Vela X-1 SA & Gamma Ray Bursts SA Coordinate

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Temporal properties of the HMXB GX over a year-long observation with SuperAGILE Evangelista et al. (submitted to ApJ )

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop The HMXB GX Orbital parameters P orb ~ P spin = 670 – 690 s e = 0.44 a sin i = ω = 310° System characteristics Discovered in 1969 (balloon obs.) d = 3kpc Hypergiant (B1 Ia+) companion Wray < M < 53 M R= 62 R  Flares regularly 1-2 days before periastron and, sometimes, at apastron

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop hard X-ray and soft X-ray orbital lightcurve all RXTE/ASM data simultaneous obs.

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop SuperAGILE observations of GX ~3.7 Ms observation

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop GX 301-2: spin history SuperAGILE spin down: ~1.3 s year -1

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Phase-resolved Pulse shape variability pre-periastron passage smoothest light curve interpulse structure main peak substructures Off-pulse level variations pulse width

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Orbital variability of pulsed fraction minimum of Pfrac during PP flare intermediate Pfrac value maximum of Pfrac value

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Wind + stream model (Leahy 2008) spherical wind Leahy quite convincingly modelled the orbital modulation of the soft X-ray emission in the GX system as driven by wind accretion plus a mass stream, drawing an Archimedes spiral path and periodically intercepting the neutron star PP flare stream (tidal interaction) N H increase (0.2 – 0.3)

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Spectral variability (HR) – (wind + stream model)? ?

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop flux keV pulsed fractionhardness Summary of source behavior along the orbit

Marco FerociINAF/IASF Rome The hard X-ray sky with SuperAGILE 7 th AGILE Workshop Despite the odd operating conditions (attitude and temperature) SuperAGILE proved to be an efficient monitor for bright hard X-ray sources. Detected sources (roughly) consistent with flux-limited LogN-LogS of persistent hard X- ray sources. GRBs discovered and arcmin-localized with a rate of ~1/month. Continuous and long-term monitoring guarantees coverage of unpredictable transient behaviour of sources, sometimes missed by scanning experiments. Long-term monitoring allows detailed timing studies of long-period X-ray pulsars (e.g., GX 301-2). SuperAGILE orbital light curves of bright sources automatically publicly distributed in nearly realtime. Improvements on the data analysis software algorithms, optimizations in processing time and larger computing power are being implemented. They will bring to:- Improved products for automated analysis - Longer integrations - Source Catalog - Image trigger for short transients and GRBs Summary & Perspectives