The HE/UHE astrophysical sources The HE/UHE astrophysical sources as optical emitters: monitoring as optical emitters: monitoring efforts and spectral analyses efforts and spectral analyses René é Hudec and collaborators Hudec and collaborators Ren Astronomical Institute, Academy of Astronomical Institute, Academy of Sciences Sciences 251 65 Ondrejov, Czech Republic 251 65 Ondrejov, Czech Republic Vulcano Workshop 2010 1
Why optical monitoring of Why optical monitoring of HE/UVE sources HE/UVE sources Multispectral analyses for good science. Very common is the situation when we have satellite/HE monitoring data covering up to ~ years, but we do not have simultaneous optical data Important goal is to recognize active states of the sources (flares, high states, etc) either to trigger the satellite or TeV observations, or, alternatively, to be able to concentrate of archival satellite data for that’s periods Vulcano Workshop 2010 2
I. Dedicated Monitoring I. Dedicated Monitoring In this regime, the narrow field telescopes observe the target frequently Important goal for robotic telescopes Vulcano Workshop 2010 3
II. The Non-Dedicated Optical II. The Non-Dedicated Optical Monitoring Monitoring In this regime, wide-field or all-sky optical images are stored covering large numbers of objects The monitors can deliver optical photometric data for objects prior and during the active/flaring states – WF coverage is important to cover as much sources as possible Photographic Sky Patrols (2 still in operation) All-Sky and Wide-Field CCD cameras Various survey projects Vulcano Workshop 2010 4
The importance of optical The importance of optical monitoring for ESA monitoring for ESA INTEGRAL INTEGRAL Hard X-ray and gamma-ray sources typically 10-80 keV Examples: Cataclysmic Variables, Blazars Vulcano Workshop 2010 5
Even gamma-ray sources do B B magnitud have optical counterparts accessible by optical telescopes 1 1 % 8 % 13% 2 Legend - B 1 = 2,29 - 5 3 38% 2 = 5 -10 4 40% 3 = 10 - 15 5 4 = 15 - 20 5 = 20 - 23 V magnitud V Legend - V 1 = 2,39 - 5 5 % 1 % 1 17% 2 = 5 -10 2 34% 3 = 10 - 15 3 4 = 15 - 20 4 5 = 20 - 21 43% 5 >90% brighter than mag 20 Optical B and V magnitudes of optically identified INTEGRAL Optical B and V magnitudes of optically identified INTEGRAL gamma-ray sources … … most are brighter than mag 20, and most are brighter than mag 20, and gamma-ray sources more than half are brighter are brighter than mag 15 than mag 15 more than half Vulcano Workshop 2010 6
V834 Cen in optical high and low state V834 Cen in optical high and low state IBIS image at optical active IBIS image at optical active state 14 mag 14 mag Object detected Object detected state This polar was probably detected by This polar was probably detected by IBIS since it was in high (active) state. . IBIS since it was in high (active) state INTEGRAL IBIS gamma-ray images IBIS image at optical low state IBIS image at optical low state 17 mag Object not detected Object not detected 17 mag It shows It s hows active active and and in ina active ctive states states. Optical monitoring . Optical monitoring of sources is important as it can indicate active of sources is important as it can indicate active intervals when the object is expected to be active also intervals when the object is expected to be active also in gamma-rays in gamma-rays Comparing optical and gamma-ray activity is difficult Comparing optical and gamma-ray activity is difficult in most cas ses due to lack of optical ( es due to lack of optical (!) data. !) data. Goal for Goal for in most ca robotic telescopes. robotic telescopes. It can be an explanation why some CV are visible and some not It can be an explanation why some CV are visible and some not Vulcano Workshop 2010 7
1ES 1959+650 1ES 1959+650 Optical LC variable blazar visible in gamma- variable blazar visible in gamma- rays by INTEGRAL IBIS only during rays by INTEGRAL IBIS only during optical flare optical flare MJD interval 53416.96-53792.96 i.e. 376.00 days [Feb 2006 - Feb 2007] IBIS LC INTEGRAL IBIS gamma-ray images MJD interval 52985.52-53203.34 i.e. 217.82 days [Dec 2004 - Jul 2005] Vulcano Workshop 2010 8
The VHE Sky The VHE Sky The VHE sky is dominated by objects which are (in many cases) also The VHE sky is dominated by objects which are (in many cases) also sources of optical emission sources of optical emission Vulcano Workshop 2010 9
Energy range Energy range covered by optical covered by optical data data Multispectral Multispectral Approach Approach Typical SEDs Typical SEDs of some of the of some of the TeV sources TeV sources TeV sources TeV sources expected to be expected to be bright optical bright optical sources sources Vulcano Workshop 2010 10
….. and some optical magnitudes of TeV sources … many do have bright optical emission LSI +61 303 mag_v 10.8 These sources can be HESS J0632+058 mag_v 9.08 in optical light Centaurus X3 mag_v 13.25 accessed by small PSR B1259-63 mag_v 10.68 telescopes and cameras HESS J1747-281 mag_v 9.25 HESS J1825-137 mag_v 11.4 LS 5039 mag_v 11.23 Vulcano Workshop 2010 11
Gamma-Ray Binaries Gamma-Ray Binaries γ -ray binaries: new class of objects with emission extending from radio to TeV LS I +61 303 has been detected at TeV energies by MAGIC: – The emission is variable – Possible hint of periodicity – The maximum of the emission happens 1/3 of the orbit away from periastron The emission produced by electrons accelerated in the interaction of the stellar and the pulsar winds. New MAGIC+multi-wavelength observations will study deeper the TeV emission (periodicity? Intra-night variability?) and correlations with radio and x-ray emissions. Vulcano Workshop 2010 12
Examples of TeV Blazars Examples of TeV Blazars in Multispectral Approach in Multispectral Approach Need to improve optical monitoring to be able to provide high-quality LCs for multi-spectral analyses Goal for robotic telescopes We also need an alert system analogous to these used in GRB satellites to provide fast response to TeV flares Vulcano Workshop 2010 13
1ES1959+650(z=0.047) 1ES1959+650(z=0.047) • Blazar famous for the orphan flare in 2002 • Blazar famous for the orphan flare in 2002 • MAGIC: Significant signal in only 6h of effective obs. in only 6h of effective obs. • MAGIC: Significant signal time ApJ, 639 (2006), 761. Lack of optical data! time ApJ, 639 (2006), 761. Lack of optical data! TeV TeV X-ray X-ray Opt. Opt. Vulcano Workshop 2010 Ciro Bigongiari 14/23
Mkn 421 2008 flare Mkn 421 2008 flare a) R-band optical light curve from GASP-WEBT (May 24–June 23); b) ASM (2-12 keV) light curve (bin size is 1 day) and XRT (2-10 keV) flux (blue triangle); c) SuperAGILE (20-60 keV, blue triangles; 1 Crab = 0.2 ph cm − 2 s − 1 ) and BAT (15-50 keV, empty black squares; 1 Crab = 0.29 ph cm − 2 s − 1 ); d) MAGIC and VERITAS (>400 GeV, empty black squares and black circles, respectively), the Crab flux > 400 GeV (horizontal dashed line), AGILE (> 100 MeV, blue triangle) e) the hardness ratio computed by using the SuperAGILE and ASM data for each day. The dashed Optical and X radiation comes from two different jet regions, each one characterized by its own variability. A possible scenarios is one in which the inner jet region would produce the Xrays and it would be at least partially transparent to the optical radiation. In contrast, the outer region can only produce lower- frequency emission Donnarumma et al., 2008 Vulcano Workshop 2010 15
Hot News Hot News These follow the topic of this workshop These follow the topic of this workshop i.e. Frontier objects in astrophysics Frontier objects in astrophysics i.e. 1. Optically pulsating magnetar 2. V407 Cygni: >100 MeV gamma-ray flare from Symbiotics Mira 3. OT in Pegasus, May 2010, and discovery of another event from the object 67 years ago 4. Possible SGR flare from gamma-ray TeV emitting binary LSI +61 303 Vulcano Workshop 2010 16
GRB 070610: Flares from a peculiar galactic burst GRB 070610: Flares from a peculiar galactic burst We recorded over 40 flare episodes Optical Up to I~16, timescales of ~20sec - 7 min Amplitudes over 4 magnitudes GRB 070610 GRB 070610 Gamma-ray Gamma-ray Galactic gamma-ray burst! Malaga Workshop 2009 17
Implications Implications A new magnifestation of magnetar activity, becoming one of the few hundred Galactic ones becoming active in 10 4 yr. First optical counterpart of SGR. The quiescent X-ray luminosity : Lx < 9 x 10 31 (D/5 kpc) 2 erg/s is intermediate between transient magnetars (including SGRs/AXPs): Lx = (2-4) x 10 35 erg/s and dim isolated neutron stars (DINs): Lx = (2-20) x 10 30 erg/s The missing link between magnetars and DINs ? Malaga Workshop 2009 18
Recommend
More recommend
