Environments of BL Lac and FSRQ blazars using clustering measurements from SDSS

Research talk given at workshop "Clustering Measurements of Active Galactic Nuclei". ESO, Garching bei Munchen, Germany. 14 Jul 2014.

Transcript

1. E N V I R O N M E N T S O F B L L A C A N D F S R Q B L A Z A R S U S I N G G A L A X I E S F R O M T H E S D S S C L U S T E R I N G M E A S U R E M E N T S O F A C T I V E G A L A C T I C N U C L E I K Y L E W I L L E T T U N I V E R S I T Y O F M I N N E S O TA , U S A G A R C H I N G B E I M Ü N C H E N , J U LY 2 0 1 4 @kwwillett
2. M r k 4 2 1 ( N A S A / S T S c I )
3. B L A Z A R / R A D I O G A L A X Y U N I F I C AT I O N S C E N A R I O B L L A C F S R Q O P T I C A L S P E C T R U M n o s t ro n g e m i s s i o n o r a b s o r p t i o n f e a t u re s E W < 5 Å b ro a d e m i s s i o n l i n e s s u p e r i m p o s e d o n s t ro n g c o n t i n u u m R A D I O J E T S h i g h l o w d o m i n a t e d m o r p h o l o g i e s H O S T G A L A X Y l u m i n o u s ( M e l l i p t i c a l s l u m i n o u s e l l i p t i c a l , 1 - 2 m a g s b r i g h t e r t h a n B L L a c h o s t s E N V I R O N M E N T m o d e r a t e l y r i c h c l u s t e r s ; A b e l l c l a s s 0 t o 1 l i e i n re g i o n s o f l o w e r g a l a x y d e n s i t i e s V I E W E D D I R E C T LY D O W N J E T A X I S
4. B L A Z A R / R A D I O G A L A X Y U N I F I C AT I O N S C E N A R I O F R I F R I I O P T I C A L S P E C T R U M w e a k o p t i c a l e m i s s i o n l i n e s ( f o r g i v e n l u m i n o s i t y ) t y p i c a l l y s t ro n g e r o p t i c a l e m i s s i o n l i n e s R A D I O J E T S l o w - l u m i n o s i t y ; i n t e n s i t y f a l l s o ff a w a y f ro m n u c l e u s h i g h l u m i n o s i t y ; e x t e n d e d l o b e s a n d h o t s p o t s H O S T G A L A X Y g i a n t e l l i p t i c a l s ; 1 0 % h a v e s o m e d e v i a t i o n f ro m r e l l i p t i c a l s ; s l i g h t l y l o w e r a v e r a g e o p t i c a l l u m i n o s i t i e s t h a n F R I s E N V I R O N M E N T m o d e r a t e l y r i c h c l u s t e r s ; o f t e n B C G s re l a t i v e l y i s o l a t e d , m o re c o n s i s t e n t w i t h f i e l d g a l a x i e s V I E W E D O F F - A X I S F R O M R A D I O J E T
5. BL Lac FSRQ FR I FR II
6. P R E V I O U S R E S U LT S • Prestage+88: BL Lac environments are consistent with FR Is • Individual studies of BL Lacs show excesses of galaxies with Abell richnesses between 0 and 1 (Falomo+96,00,Pesce +94,Fried+93,Smith+95) in agreement with FR Is (Hill+91) • Owen+95: surveys of powerful radio sources in clusters revealed many FR Is, but no BL Lacs. • Wurtz+93,97: BL Lacs are found in poor clusters, with richness increasing with redshift. Trends are more similar to FR II than FR I. • Urry+00, Falomo+00, Pesce+02: enhancements in BL Lac environments over average density. High number of close companions (< 20 kpc) identified. BL Lac FSRQ FR I FR II
7. P R E V I O U S R E S U LT S • Prestage+88: BL Lac environments are consistent with FR Is • Individual studies of BL Lacs show excesses of galaxies with Abell richnesses between 0 and 1 (Falomo+96,00,Pesce +94,Fried+93,Smith+95) in agreement with FR Is (Hill+91) • Owen+95: surveys of powerful radio sources in clusters revealed many FR Is, but no BL Lacs. • Wurtz+93,97: BL Lacs are found in poor clusters, with richness increasing with redshift. Trends are more similar to FR II than FR I. • Urry+00, Falomo+00, Pesce+02: enhancements in BL Lac environments over average density. High number of close companions (< 20 kpc) identified. M I S S I N G : U P - T O - D AT E S T U D I E S O F T H E B L A Z A R P O P U L AT I O N S W I T H I M P R O V E D S TAT I S T I C S A N D D E E P E R I M A G I N G BL Lac FSRQ FR I FR II
8. S PAT I A L C O VA R I A N C E A M P L I T U D E • Developed by Longair & Seldner (1979) • Measures number of neighboring galaxies in projection around a single point • Pros: independent of magnitude limit or counting radius; can be used without full 3D positions • Cons: statistical measurement with large error bars (~50-100%) on individual points
9. S PAT I A L C O VA R I A N C E A M P L I T U D E • Developed by Longair & Seldner (1979) • Measures number of neighboring galaxies in projection around a single point • Pros: independent of magnitude limit or counting radius; can be used without full 3D positions • Cons: statistical measurement with large error bars (~50-100%) on individual points
10. S PAT I A L C O VA R I A N C E A M P L I T U D E • Developed by Longair & Seldner (1979) • Measures number of neighboring galaxies in projection around a single point • Pros: independent of magnitude limit or counting radius; can be used without full 3D positions • Cons: statistical measurement with large error bars (~50-100%) on individual points B = (Nt Nbg) (3 )D 3✓ 1 2A✓I [M(m, z)]
11. S A M P L E S E L E C T I O N • Roma-BZCAT (2,728 blazars) • Optically-selected blazars from SDSS • 723 BL Lacs (Plotkin et al. 2010) • 185 FSRQs (Chen et al. 2009) • TeV-Cat γ-ray selected objects (148 blazars)
12. D I S T R I B U T I O N O F B L A Z A R S PAT I A L C O R R E L AT I O N A M P L I T U D E S −1500−1000 −500 0 500 1000 1500 B gB [Mpc−1.77] 0 50 100 150 200 250 Number of blazars <B gB >= 111±257 <B gB >= 116±278 FSRQ BL Lac
13. 0.0 0.2 0.4 0.6 Blazar redshift −2000 −1000 0 1000 2000 B gB 0.0 0.2 0.4 0.6 Blazar redshift −2000 −1000 0 1000 2000 B gB FSRQ BL Lac B L A Z A R C L U S T E R I N G A S F U N C T I O N O F R E D S H I F T • 757 blazars have measurable BgB values from SDSS data • Richer clusters are found at z > 0.5, increasing by a factor of 2-3 • Trend is the same for both BL Lacs and FSRQs 0.0 0.2 0.4 0.6 0 -1000 -2000 2000 1000 BgB z BL Lac FSRQ
14. C L U S T E R I N G VA L U E S A S F U N C T I O N O F M U LT I WAV E L E N G T H P R O P E R T I E S 102310241025102610271028 −1000 −500 0 500 1000 1500 2000 102310241025102610271028 1.4 GHz L i [W/Hz] −1000 −500 0 500 1000 1500 2000 B gB l = −0.01 l = 0.02 BL Lac FSRQ −28−26−24−22−20−18−16 M R −1000 −500 0 500 1000 1500 2000 B gB l = −0.04 l = −0.01 104210431044104510461047 (0.1−2.4) keV iL i [erg/s] −1000 −500 0 500 1000 1500 2000 B gB l = −0.03 l = 0.10 −0.20.00.20.40.60.81.0 _ (radio−optical) −1000 −500 0 500 1000 1500 2000 B gB l = −0.03 l = 0.06 0.5 1.0 1.5 2.0 2.5 _ (optical−X−ray) −1000 −500 0 500 1000 1500 2000 B gB l = −0.04 l = 0.14 0.40.50.60.70.80.91.0 _ (radio−X−ray) −1000 −500 0 500 1000 1500 2000 B gB l = 0.07 l = 0.16
15. C L U S T E R I N G A N D T H E B L A Z A R S E Q U E N C E / E N V E L O P E 12 13 14 15 16 17 44.0 44.5 45.0 45.5 46.0 46.5 47.0 12 13 14 15 16 17 log (ipeak ) [Hz] 44.0 44.5 45.0 45.5 46.0 46.5 47.0 log (iL i ) [erg s−1] BL Lac FSRQ 0.1 0.2 0.3 0.4 0.5 0.6 0.7 z
16. C L U S T E R I N G A N D T H E B L A Z A R S E Q U E N C E / E N V E L O P E 12 13 14 15 16 17 44.0 44.5 45.0 45.5 46.0 46.5 47.0 12 13 14 15 16 17 log (ipeak ) [Hz] 44.0 44.5 45.0 45.5 46.0 46.5 47.0 log (iL i ) [erg s−1] BL Lac FSRQ 0.1 0.2 0.3 0.4 0.5 0.6 0.7 z
17. E N V I R O N M E N T S O F P O W E R F U L R A D I O G A L A X I E S 3 C 4 4 9 , C y g A i m a g e s c o u r t e s y A U I / N R A O • Measured B gg for 239 morphologically- classified radio galaxies in the SDSS footprint • Radio galaxies have similar spatial correlation amplitudes to both types of blazars • FR I: 150 ± 533 Mpc -1.77 • FR II: 175 ± 364 Mpc -1.77 • FR I galaxies exist in similar environments to FR II galaxies • No strong evolution in B gg as a function of redshift
18. R A D I O G A L A X Y Z O O E X PA N D I N G T H E S A M P L E S I Z E
19. VA R I A B I L I T Y A S F U N C T I O N O F E N V I R O N M E N T • Galaxies with UHECR emission can only show it if magnetic fields are not isotropized by nearby companions • Emission caused by UHECR should not rapidly vary in flux, since the source size is large. • Prediction: low variability TeV blazars should live in low-density environments. • Of the two known TeV blazars in SDSS with low variability, one is in a an underdense and the other in a moderately overdense cluster R a z z a q u e + 1 2 HESS VERITAS Deabsorbed Deabsorbed
20. VA R I A B I L I T Y A S F U N C T I O N O F E N V I R O N M E N T • Galaxies with UHECR emission can only show it if magnetic fields are not isotropized by nearby companions • Emission caused by UHECR should not rapidly vary in flux, since the source size is large. • Prediction: low variability TeV blazars should live in low-density environments. • Of the two known TeV blazars in SDSS with low variability, one is in a an underdense and the other in a moderately overdense cluster z B 1 E S 0 2 2 9 + 2 0 0 0 . 1 4 - 2 9 9 ± 2 5 9 R G B J 0 1 5 2 + 0 1 7 0 . 0 8 3 1 6 ± 3 6 6 R a z z a q u e + 1 2 HESS VERITAS Deabsorbed Deabsorbed
21. P H Y S I C A L M E C H A N I S M S F O R D I F F E R E N T B L A Z A R C L U S T E R I N G S T R E N G T H S • Rapidly changing gas density or galaxy-galaxy interaction rate causes cause AGN in rich clusters to fade. This would transform more quasars into BL Lacs. • FR II sources are less likely to be in high-density environments; increased external gas pressure in ICM suppresses collimated jet with advancing hot spot • Inflow of gas/dust from nearby neighbors/ICM changes the accretion efficiency of the BH
22. 0.0 0.2 0.4 0.6 0.8 Blazar redshift −2000 −1000 0 1000 2000 B gB 0.0 0.2 0.4 0.6 0.8 Blazar redshift −2000 −1000 0 1000 2000 B gB FSRQ BL Lac FSRQ C O N C L U S I O N S • The unification paradigm of blazars with radio galaxies can be indirectly probed by examining their Mpc-scale environments • 757 blazars + clustering galaxies from SDSS is the largest sample so far constructed • Blazars exist in moderately over- dense regions, but there is no significant difference between companions of the BL Lac and FSRQ populations 0.0 0.2 0.4 0.6 0 -1000 -2000 2000 1000 BgB z BL Lac BgB =