A Pair of Compact Red Galaxies at Redshift 2.38, Immersed in a 100 Kiloparsec Scale Lyα Nebula

Francis, Paul; Williger, G. M.; Collins, Nicholas R.; Palunas, Povilas; Malumuth, E. M.; Woodgate, B. E.; Teplitz, Harry I.; Smette, A.; Sutherland, Ralph S.; Danks, A. C.; Hill, Robert S.; Lindler, D. J.; Kimble, Randy A.; Heap, Sara R.; Hutchings, J. B.

doi:10.1086/321417

Cited by 101 publications

(122 citation statements)

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“…Nevertheless, this overdense field showed clearly an excess of extended sources with respect to "blank" observation suggesting a possible relation between galaxy (or AGN) overdensities and extended Lyα emission. Similarly, deep narrow band imaging obtained by Palunas et al (2004) of the overdense field at z∼ 2.38 found by Francis et al (2001), revealed a large Lyα blob with sizes compatible with Steidel's LAB1 and several smaller nebulae around galaxies.…”

Section: Lyα Blobssupporting

confidence: 55%

“…Extended Lyα nebulae around galaxies that did not contain optically bright or radioloud AGN in overdense fields were already known before the observations of Steidel et al (2000), e.g. Francis et al (1996) and later re-observations published in Francis et al (2001), and Keel et al (1999), although in most cases hints of obscured AGN were present in these studies. Steidel "blobs" however were the first one in this category to exceed the "giant Lyα Nebula" size of 100 kpc.…”

Section: Lyα Blobsmentioning

confidence: 73%

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Gas Accretion and Giant Lyα Nebulae

Cantalupo

2017

Astrophysics and Space Science Library

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Several decades of observations and discoveries have shown that highredshift AGN and massive galaxies are often surrounded by giant Lyα nebulae extending in some cases up to 500 kpc in size. In this chapter, I review the properties of the such nebulae discovered at z > 2 and their connection with gas flows in and around galaxies and their halos. In particular, I show how current observations are used to constrain the physical properties and origin of the emitting gas in terms of the Lyα photon production processes and kinematical signatures. The emerging picture from these studies suggest that recombination radiation is the most viable scenario to explain the observed Lyα luminosities and Surface Brightness for the large majority of the nebulae and imply that a significant amount of dense (n > 1 cm −3 ), ionized and cold (T ∼ 10 4 K) "clumps" should be present within and around the halos of massive galaxies. Spectroscopic studies suggest that, among the giant Lyα nebulae, the one associated with radio-loud AGN should have kinematics dominated by strong, ionized outflows within at least the inner 30-50 kpc. Radio-quiet nebulae instead present more quiescent kinematics compatible with "stationary" situation and, in some cases, suggestive of rotating structures. However, definitive evidences for accretion onto galaxies of the gas associated with the giant Lyα emission are not unambiguously detected yet. Deep surveys currently ongoing using other bright, non-resonant lines such as Hydrogen Hα and He II 1640 will be crucial to search for clearer signatures of cosmological gas accretion onto galaxies and AGN.

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Section: Lyα Blobssupporting

confidence: 55%

Section: Lyα Blobsmentioning

confidence: 73%

Gas Accretion and Giant Lyα Nebulae

Cantalupo

2017

Astrophysics and Space Science Library

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“…Recently there has been great interest in the highly extended (∼30-200 kpc in projected linear extent) Lyα line-emitting nebulae (L Lyα ∼ 10 43-44 erg s −1 ) identified in high-redshift narrowband surveys: "Lyα Blobs" (LABs; Fynbo et al 1999;Keel et al 1999;Steidel et al 2000;Francis et al 2001;Palunas et al 2004;Matsuda et al 2004;Dey et al 2005;Smith et al 2008). The most important questions in LAB studies remain unanswered: how are they formed and what maintains their power?…”

Section: Introductionmentioning

confidence: 99%

THECHANDRADEEP PROTOCLUSTER SURVEY: Lyα BLOBS ARE POWERED BY HEATING, NOT COOLING

Geach

Alexander

Lehmer

et al. 2009

ApJ

130

228

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We present the results of a 400 ks Chandra survey of 29 extended Lyα emitting nebulae (Lyα Blobs, LABs) in the z = 3.09 protocluster in the SS A22 field. We detect luminous X-ray counterparts in five LABs, implying a large fraction of active galactic nuclei (AGN) in LABs, f AGN = 17 +12 −7 % down to L 2-32 keV ∼ 10 44 erg s −1 . All of the AGN appear to be heavily obscured, with spectral indices implying obscuring column densities of N H > 10 23 cm −2 . The AGN fraction should be considered a lower limit, since several more LABs not detected with Chandra show AGN signatures in their mid-infrared (mid-IR) emission. We show that the UV luminosities of the AGN are easily capable of powering the extended Lyα emission via photoionization alone. When combined with the UV flux from a starburst component, and energy deposited by mechanical feedback, we demonstrate that "heating" by a central source, rather than gravitational cooling is the most likely power source of LABs. We argue that all LABs could be powered in this manner, but that the luminous host galaxies are often just below the sensitivity limits of current instrumentation, or are heavily obscured. No individual LABs show evidence for extended X-ray emission, and a stack equivalent to a 9 Ms exposure of an average LAB also yields no statistical detection of a diffuse X-ray component. The resulting diffuse X-ray/Lyα luminosity limit implies there is no hot (T 10 7 K) gas component in these halos, and also rules out inverse Compton scattering of cosmic microwave background photons, or local far-IR photons, as a viable power source for LABs.

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“…Searches for Lyα emission in the high-redshift Universe have in the last decade found many sources of a type called Lyα "blobs" (Fynbo et al 1999;Keel et al 1999;Steidel et al 2000;Francis et al 2001;Matsuda et al 2004;Palunas et al 2004;Weidinger et al 2004;Dey et al 2005;Villar-Martín et al 2005;Nilsson et al 2006). Lyα blobs must be considered the extreme end of Based on observations done with i) European Southern Observatory (ESO) utilizing 8.2m Very Large Telescope (VLT) X-shooter spectrograph on Cerro Paranal in the Atacama Desert, northern Chile.…”

Section: Introductionmentioning

confidence: 99%

A Lyαblob andz_abs ≈ z_emdamped Lyαabsorber in the dark matter halo of the binary quasar Q 0151+048

Zafar

Møller

Ledoux

et al. 2011

A&A

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Context. Q 0151+048 is a physical quasar (QSO) pair at z ∼ 1.929 with a separation of 3.3 arcsec on the sky. In the spectrum of the brighter member of this pair, Q 0151+048A, a damped Lyα absorber (DLA) is observed at a higher redshift. We have previously detected the host galaxies of both QSOs, as well as a Lyα blob whose emission surrounding Q 0151+048A extends over 5× 3.3 arcsec. Aims. We seek to constrain the geometry of the system and understand the possible relations between the DLA, the Lyα blob, and the two QSOs. We also aim at characterizing the former two objects in more detail. Methods. To study the nature of the Lyα blob, we performed low-resolution, long-slit spectroscopy with the slit aligned with the extended emission. We also observed the whole system using the medium-resolution VLT/X-shooter spectrograph and the slit aligned with the two QSOs. The systemic redshift of both QSOs was determined from rest-frame optical emission lines redshifted into the NIR. We employed line-profile fitting technique, to measure metallicities and the velocity width of low-ionization metal absorption lines associated to the DLA and photo-ionization modeling to characterize the DLA further. Results. We measure systemic redshifts of z em(A) = 1.92924 ± 0.00036 and z em(B) = 1.92863 ± 0.00042 from the H β and H α emission lines, respectively. In other words, the two QSOs have identical redshifts within 2σ. From the width of Balmer emission lines and the strength of the rest-frame optical continuum, we estimate the masses of the black holes of the two QSOs to be 10 9.33 M and 10 8.38 M for Q 0151+048A and Q 0151+048B, respectively. We then use the correlation between black hole mass and dark matter halo mass to infer the mass of the dark matter halos hosting the two QSOs: 10 13.74 M and 10 13.13 M for Q 0151+048A and Q 0151+048B, respectively. We observe a velocity gradient along the major axis of the Lyα blob consistent with the rotation curve of a large disk galaxy, but it may also be caused by gas inflow or outflow. We detect residual continuum in the DLA trough, which we interpret as emission from the host galaxy of Q 0151+048A. The derived H 0 column density of the DLA is log N H 0 = 20.34 ± 0.02 cm −2 . Metal column densities are also determined for a number of low-ionization species resulting in an overall metallicity of 0.01 Z . We detect C ii * , which allows us to make a physical model of the DLA cloud. Conclusions. From the systemic redshifts of the QSOs, we conclude that the Lyα blob is associated with Q 0151+048A rather than with the DLA. The DLA must be located in front of both the Lyα blob and Q 0151+048A at a distance greater than 30 kpc and has a velocity relative to the blob of 640 ± 70 km s −1 . The two quasars accrete at normal Eddington ratios. The DM halo of this double quasar will grow to the mass of our local supercluster at z = 0. We point out that those objects therefore form an ideal laboratory to study the physical interactions in a z = 2 precursor of our local supercluster.

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A Pair of Compact Red Galaxies at Redshift 2.38, Immersed in a 100 Kiloparsec Scale Lyα Nebula

Cited by 101 publications

References 60 publications

Gas Accretion and Giant Lyα Nebulae

Gas Accretion and Giant Lyα Nebulae

THECHANDRADEEP PROTOCLUSTER SURVEY: Lyα BLOBS ARE POWERED BY HEATING, NOT COOLING

A Lyαblob andz_abs ≈ z_emdamped Lyαabsorber in the dark matter halo of the binary quasar Q 0151+048

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A Pair of Compact Red Galaxies at Redshift 2.38, Immersed in a 100 Kiloparsec Scale Lyα Nebula

Cited by 101 publications

References 60 publications

Gas Accretion and Giant Lyα Nebulae

Gas Accretion and Giant Lyα Nebulae

THECHANDRADEEP PROTOCLUSTER SURVEY: Lyα BLOBS ARE POWERED BY HEATING, NOT COOLING

A Lyαblob andzabs ≈ zemdamped Lyαabsorber in the dark matter halo of the binary quasar Q 0151+048

Contact Info

Product

Resources

About

A Lyαblob andz_abs ≈ z_emdamped Lyαabsorber in the dark matter halo of the binary quasar Q 0151+048