Publications by James Binney


Astronomy - Triangulating the galaxy

SCIENCE 311 (2006) 44-45

JJ Binney


Triangulating the galaxy

Science 311 (2006) 44-45

JJ Binney


Mechanical heating by active galaxies

Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 363 (2005) 655-665

MC Begelman, M Ruszkowski, J Binney

Jets and winds are significant channels for energy loss from accreting black holes. These outflows mechanically heat their surroundings, through shocks as well as gentler forms of heating. We discuss recent efforts to understand the nature and distribution of mechanical heating by central active galactic nuclei (AGN) in clusters of galaxies, using numerical simulations and analytic models. Specifically, we will discuss whether the relatively gentle 'effervescent heating' mechanism can compensate for radiative losses in the central regions of clusters, and account for the excess entropy observed at larger radii. J. Binney (2005 Phil. Trans. R. Soc. A, 363, 739-749, doi: 10.1098/rsta.2004.1520) discusses the possible role of violent, episodic heating by AGN in clusters. © 2005 The Royal Society.


Active galaxies and radiative heating

Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 363 (2005) 667-683

JP Ostriker, L Ciotti, MC Begelman, J Binney

There is abundant evidence that heating processes in the central regions of elliptical galaxies have both prevented large-scale cooling flows and assisted in the expulsion of metal rich gas. We now know that each such spheroidal system harbours in its core a massive black hole weighing ca. 0.13% of the mass in stars and also know that energy was emitted by each of these black holes with an efficiency exceeding 10% of its rest mass. Since, if only 0.5% of that radiant energy were intercepted by the ambient gas, its thermal state would be drastically altered, it is worth examining in detail the interaction between the out-flowing radiation and the equilibrium or inflowing gas. On the basis of detailed hydrodynamic computations we find that relaxation oscillations are to be expected with the radiative feedback quite capable of regulating both the growth of the central black hole and also the density and thermal state of the gas in the galaxy, Mechanical input of energy by jets may assist or dominate over these radiative effects. We propose specific observational tests to identify systems which have experienced strong bursts of radiative heating from their central black holes. © 2005 The Royal Society.


The legacy and large-scale distribution of active galaxies

Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 363 (2005) 613-619

S Tremaine, J Binney, JP Ostriker, CS Frenk

If accretion onto massive black holes is the power source for active galaxies, then nearby galaxies should contain 'dead quasars': black holes that do not shine, either because they are starved for fuel or because they accrete with low radiative efficiency. This article briefly reviews the evidence that most inactive galaxies contain black holes at their centres, and how the local distribution of black holes is related to the population of active galaxies. © 2005 The Royal Society.


The cosmological context of extra-planar gas

Extra-Planar Gas 331 (2005) 131-138

J Binney


Modelling the Galaxy for Gaia

European Space Agency, (Special Publication) ESA SP (2005) 89-95

J Binney

Techniques for the construction of dynamical Galaxy models should be considered essential infrastructure that should be put in place before Gaia flies. Three possible modelling techniques are discussed. Although one of these seems to have significantly more potential than the other two, at this stage work should be done on all three. A major effort is needed to decide how to make a model consistent with a catalogue such as that which Gaia will produce. Given the complexity of the problem, it is argued that a hierarchy of models should be constructed, of ever increasing complexity and quality of fit to the data. The potential that resonances and tidal streams have to indicate how a model should be refined is briefly discussed.


Integral field spectroscopy of 23 spiral bulges

Astrophysical Journal, Supplement Series 160 (2005) 76-86

D Batcheldor, D Axon, D Merritt, MA Hughes, A Marconi, J Binney, A Capetti, M Merrifield, C Scarlata, W Sparks

We have obtained integral-field spectroscopy for 23 spiral bulges using INTEGRAL on the William Herschel Telescope and SPIRAL on the Anglo-Australian Telescope. This is the first two-dimensional survey directed solely at the bulges of spiral galaxies. Eleven galaxies of the sample do not have previous measurements of the stellar velocity dispersion (σ*). These data are designed to complement our Space Telescope Imaging Spectrograph program for estimating black hole masses in the range 106-108 M ⊙ using gas kinematics from nucleated disks. These observations will serve to derive the stellar dynamical bulge properties using the traditional Mg b and Ca II triplets. We use both cross-correlation and maximum penalized likelihood to determine projected σ* in these systems and present radial velocity fields, major axis rotation curves, curves of growth, and σ* fields. Using cross-correlation to extract the low-order two-dimensional stellar dynamics we generally see coherent radial rotation and irregular velocity dispersion fields suggesting that is a nontrivial parameter to estimate. © 2005, The American Astronomical Society. All rights reserved.


Nuclear properties of nearby spiral galaxies from nubble Space Telescope NICMOS imaging and STIS spectroscopy

Astronomical Journal 130 (2005) 73-83

MA Hughes, D Axon, J Atkinson, A Alonso-Herrero, C Scarlata, A Marconi, D Batcheldor, J Binney, A Capetti, CM Carollo, L Dressel, J Gerssen, D Macchetto, W Maciejewski, M Merrifield, M Ruiz, W Sparks, M Stiavelli, Z Tsvetanov

We investigate the central regions of 23 spiral galaxies using Space Telescope Imaging Spectrograph (STIS) spectroscopy and archival Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) imaging. The sample is taken from our program to determine the masses of central massive black holes (MBHs) in 54 nearby spiral galaxies. Stars are likely to contribute significantly to any dynamical central mass concentration that we find in our MBH program, and this paper is part of a series to investigate the nuclear properties of these galaxies. We use the Nuker law to fit surface brightness profiles, derived from the NICMOS images, to look for nuclear star clusters and find possible extended sources in three of the 23 galaxies studied (13%). The fact that this fraction is lower than that inferred from optical Bubble Space Telescope studies is probably due to the greater spatial resolution of those studies. Using R - H and J - H colors and equivalent widths of Hα emission (from the STIS spectra), we investigate the nature of the stellar population with evolutionary models. Under the assumption of hot stars ionizing the gas, as opposed to a weak active galactic nucleus (AGN), we find that there are young stellar populations (∼ 10-20 Myr); however, these data do not allow us to determine what percentage of the total nuclear stellar population they form. In addition, in an attempt to find any unknown AGN, we use [N II] and [S II] line flux ratios (relative to Hα) and find tentative evidence for weak AGNs in NGC 1300 and NGC 4536. © 2005. The American Astronomical Society. All rights reserved.


Black holes, cuspy atmospheres and galaxy formation

Philosophical Transactions of the Royal Society 363 (2005) 739-749

JJ Binney


The impact of active galaxies on the Universe at large - Preface

PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES 363 (2005) 611-612

J Binney, KM Blundell, JP Ostriker, SDM White


Commission 28: Galaxies

Proceedings of the International Astronomical Union 1 (2005) 281-289

EM Sadler, F Combes, JJ Binney, AP Fairall, TM Heckman, V Karachentseva, GR Knapp, RC Kraan-Korteweg, B Leibundgut, SJ Lilly, JV Narlikar, S Okamura

This report gives a brief overview of some of the activities and developments in extragalactic research over the past three years. © 2007 International Astronomical Union.


Nuclear properties of a sample of nearby spiral galaxies from Hubble Space Telescope STIS imaging

Astronomical Journal 128 (2004) 1124-1137

C Scarlata, M Stiavelli, MA Hughes, D Axon, A Alonso-Herrero, J Atkinson, D Batcheldor, J Binney, A Capetti, CM Carollo, L Dressel, J Gerssen, D Macchetto, W Maciejewski, A Marconi, M Merrifield, M Ruiz, W Sparks, Z Tsvetanov, RP Van Der Marel

We present surface photometry for the central regions of a sample of 48 spiral galaxies (mostly unbarred and barred of type Sbc or Sc) observed with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. Surface brightness profiles (SBPs) were derived and modeled with a Nuker law. We also analyzed archival Wide Field Planetary Camera 2 images with a larger field of view, which are available for 18 galaxies in our sample. We modeled the extracted bulge SBPs with an exponential, an r1/4, or an r n profile. In agreement with previous studies, we find that bulges of Sbc galaxies fall into two categories: bulges well described by an exponential profile and those well described by an r1/4 profile. Only one galaxy requires the use of a more general Sérsic profile to properly describe the bulge. Nuclear photometrically distinct components are found in ∼55% of the galaxies. For those that we classify as star clusters on the basis of their resolved extent, we find absolute magnitudes that are brighter on average than those previously identified in spiral galaxies. This might be due to a bias in our sample toward star-forming galaxies, combined with a trend for star-forming galaxies to host brighter central clusters.


Nuclear properties of a sample of nearby spiral galaxies from Hubble Space Telescope STIS imaging

ASTRONOMICAL JOURNAL 128 (2004) 1124-1137

C Scarlata, M Stiavelli, MA Hughes, D Axon, A Alonso-Herrero, J Atkinson, D Batcheldor, J Binney, A Capetti, CM Carollo, L Dressel, J Gerssen, D Macchetto, W Maciejewski, A Marconi, M Merrifield, M Ruiz, W Sparks, Z Tsvetanov, RP van der Marel


Conference summary

DARK MATTER IN GALAXIES (2004) 3-13

J Binney


Two-body relaxation in modified Newtonian dynamics

Monthly Notices of the Royal Astronomical Society 351 (2004) 285-291

L Ciotti, J Binney

A naive extension to modified Newtonian dynamics (MOND) of the standard computation of the two-body relaxation time t 2b implies that 2b is comparable to the crossing time regardless of the number W of stars in the system. This computation is questionable in view of the non-linearity of MOND's field equation. A non-standard approach to the calculation of t 2b is developed that can be extended to MOND whenever discreteness noise generates force fluctuations that are small compared to the mean-field force. It is shown that this approach yields standard Newtonian results for systems in which the mean density profile is either plane-parallel or spherical. In the plane-parallel case, we find that in the deep-MOND regime t 2b scales with N as in the Newtonian case, but is shorter by the square of the factor by which MOND enhances the gravitational force over its Newtonian value for the same system. Near the centre of a spherical system that is in the deep-MOND regime, we show that the fluctuating component of the gravitational force is never small compared to the mean-field force; this conclusion surprisingly even applies to systems with a density cusp that keeps the mean-field force constant to arbitrarily small radius, and suggests that a cuspy centre can never be in the deep-MOND regime. Application of these results to dwarf galaxies and groups and clusters of galaxies reveals that in MOND luminosity segregation should be far advanced in groups and clusters of galaxies, two-body relaxation should have substantially modified the density profiles of galaxy groups, while objects with masses in excess of ∼10 M⊙ should have spiralled to the centres of dwarf galaxies.


On the origin of the galaxy luminosity function

Monthly Notices of the Royal Astronomical Society 347 (2004) 1093-1096

J Binney

Evidence is summarized which suggests that when a protogalaxy collapses, a fraction f of its gas fails to heat to the virial temperature, where f is large for haloes less massive than the value M* associated with L* galaxies. Stars and galaxies form only from the cool gas fraction. Hot gas is ejected from low-mass systems as in conventional semi-analytic models of galaxy formation. In high-mass systems it is retained but does not cool and form stars. Instead it builds up as a largely inert atmosphere, in which cooling is inhibited by an episodically active galactic nucleus. Cold gas frequently falls into galactic haloes. In the absence of a dense atmosphere of virial-temperature gas it builds up on nearly circular orbits and can be observed in the 21-cm line of H I. When there is a sufficiently dense hot atmosphere, cold infalling gas tends to be ablated and absorbed by the hot atmosphere before it can form stars. The picture nicely explains away the surfeit of high-luminosity galaxies that has recently plagued semi-analytic models of galaxy formation, replacing them by systems of moderate luminosity from old stars and large X-ray luminosities from hot gas.


An atlas of Hubble Space Telescope spectra and images of nearby spiral galaxies

ASTRONOMICAL JOURNAL 126 (2003) 742-761

MA Hughes, A Alonso-Herrero, D Axon, C Scarlata, J Atkinson, D Batcheldor, J Binney, A Capetti, CM Carollo, L Dressel, J Gerssen, D Macchetto, W Maciejewski, A Marconi, M Merrifield, M Ruiz, W Sparks, M Stiavelli, Z Tsvetanov, R van der Marel


Is there really a black hole at the center of NGC 4041? Constraints from gas kinematics

ASTROPHYSICAL JOURNAL 586 (2003) 868-890

A Marconi, DJ Axon, A Capetti, W Maciejewski, J Atkinson, D Batcheldor, J Binney, M Carollo, L Dressel, H Ford, J Gerssen, MA Hughes, D Macchetto, MR Merrifield, C Scarlata, W Sparks, M Stiavelli, Z Tsvetanov, RP van der Marel


An atlas of Hubble space telescope spectra and images of nearby spiral galaxies

Astronomical Journal 126 (2003) 742-761

MA Hughes, A Alonso-Herrero, D Axon, C Scarlata, J Atkinson, D Batcheldor, J Binney, A Capetti, CM Carollo, L Dressel, J Gerssen, D Macchetto, W Maciejewski, A Marconi, M Merrifield, M Ruiz, W Sparks, M Stiavelli, Z Tsvetanov, R Van der Marel

We have observed 54 nearby spiral galaxies with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope to obtain optical long-slit spectra of nuclear gas disks and STIS optical (∼R band) images of the central 5″ × 5′ of the galaxies. These spectra are being used to determine the velocity field of nuclear disks and hence to detect the presence of central massive black holes. Here we present the spectra for the successful observations. Dust obscuration can be significant at optical wavelengths, and so we also combine the STIS images with archival Near-Infrared Camera and Multi-Object Spectrometer H-band images to produce color maps to investigate the morphology of gas and dust in the central regions. We find a great variety in the different morphologies, from smooth distributions to well-defined nuclear spirals and dust lanes.

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