Publications by Martin Bureau

K-CLASH: Strangulation and ram pressure stripping in galaxy cluster members at 0.3 &lt; z &lt; 0.6

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 496 (2020) 3841-3861

SP Vaughan, AL Tiley, RL Davies, LJ Prichard, SM Croom, M Bureau, JP Stott, A Bunker, M Cappellari, B Ansarinejad, MJ Jarvis

&lt;jats:title&gt;ABSTRACT&lt;/jats:title&gt; &lt;jats:p&gt;Galaxy clusters have long been theorized to quench the star formation of their members. This study uses integral-field unit observations from the K-band MultiObject Spectrograph (KMOS) &#x2013; Cluster Lensing And Supernova survey with Hubble (CLASH) survey (K-CLASH) to search for evidence of quenching in massive galaxy clusters at redshifts 0.3 &amp;amp;lt; z &amp;amp;lt; 0.6. We first construct mass-matched samples of exclusively star-forming cluster and field galaxies, then investigate the spatial extent of their H&#x2009;&#x3B1; emission and study their interstellar medium conditions using emission line ratios. The average ratio of H&#x2009;&#x3B1; half-light radius to optical half-light radius ($r_{\mathrm{e}, {\rm {H}\,\alpha }}/r_{\mathrm{e}, R_{\mathrm{c} } }$) for all galaxies is 1.14&#xA0;&#xB1;&#xA0;0.06, showing that star formation is taking place throughout stellar discs at these redshifts. However, on average, cluster galaxies have a smaller $r_{\mathrm{e}, {\rm {H}\alpha }}/r_{\mathrm{e}, R_{\mathrm{c} } }$ ratio than field galaxies: &#x2329;$r_{\mathrm{e}, {\rm {H}\alpha }}/r_{\mathrm{e}, R_{\mathrm{c} } }$&#x232A;&#xA0;= 0.96&#xA0;&#xB1;&#xA0;0.09 compared to 1.22&#xA0;&#xB1;&#xA0;0.08 (smaller at a 98&#x2009;per&#x2009;cent credibility level). These values are uncorrected for the wavelength difference between H&#x2009;&#x3B1; emission and Rc-band stellar light but implementing such a correction only reinforces our results. We also show that whilst the cluster and field samples follow indistinguishable mass&#x2013;metallicity (MZ) relations, the residuals around the MZ relation of cluster members correlate with cluster-centric distance; galaxies residing closer to the cluster centre tend to have enhanced metallicities (significant at the 2.6&#x3C3; level). Finally, in contrast to previous studies, we find no significant differences in electron number density between the cluster and field galaxies. We use simple chemical evolution models to conclude that the effects of disc strangulation and ram-pressure stripping can quantitatively explain our observations.&lt;/jats:p&gt;

Revealing the Intermediate Mass Black Hole at the Heart of Dwarf Galaxy NGC404 with Sub-parsec Resolution ALMA Observations

Monthly Notices of the Royal Astronomical Society Oxford University Press 496 (2020) 4061-4078

M Bureau, M Cappellari, L Liu, M Smith

We estimate the mass of the intermediate-mass black hole at the heart of the dwarf elliptical galaxy NGC 404 using Atacama Large Millimeter/submillimeter Array (ALMA) observations of the molecular interstellar medium at an unprecedented linear resolution of ≈0.5 pc, in combination with existing stellar kinematic information. These ALMA observations reveal a central disc/torus of molecular gas clearly rotating around the black hole. This disc is surrounded by a morphologically and kinematically complex flocculent distribution of molecular clouds, that we resolve in detail. Continuum emission is detected from the central parts of NGC 404, likely arising from the Rayleigh–Jeans tail of emission from dust around the nucleus, and potentially from dusty massive star-forming clumps at discrete locations in the disc. Several dynamical measurements of the black hole mass in this system have been made in the past, but they do not agree. We show here that both the observed molecular gas and stellar kinematics independently require a ≈ 5 × 105 M black hole once we include the contribution of the molecular gas to the potential. Our best estimate comes from the high-resolution molecular gas kinematics, suggesting the black hole mass of this system is 5.5+4.1−3.8×105 M (at the 99% confidence level), in good agreement with our revised stellar kinematic measurement and broadly consistent with extrapolations from the black hole mass – velocity dispersion and black hole mass – bulge mass relations. This highlights the need to accurately determine the mass and distribution of each dynamically important component around intermediate-mass black holes when attempting to estimate their masses.

K-CLASH: spatially-resolving star-forming galaxies in field and cluster environments at z ≈ 0.2-0.6

Monthly Notices of the Royal Astronomical Society Oxford University Press (2020)

AL Tiley, JP Stott, R Davies, LJ Prichard, A Bunker, M Bureau, M Cappellari, M Jarvis, A Robotham, L Cortese, S Bellstedt, B Ansarinejad

We present the KMOS-CLASH (K-CLASH) survey, a K-band Multi-Object Spectrograph (KMOS) survey of the spatially-resolved gas properties and kinematics of 191 (predominantly blue) Hα-detected galaxies at 0.2 ≲ z ≲ 0.6 in field and cluster environments. K-CLASH targets galaxies in four Cluster Lensing And Supernova survey with Hubble (CLASH) fields in the KMOS IZ-band, over 7′ radius (≈2–3 Mpc) fields-of-view. K-CLASH aims to study the transition of star-forming galaxies from turbulent, highly star-forming disc-like and peculiar systems at z ≈ 1–3, to the comparatively quiescent, ordered late-type galaxies at z ≈ 0, and to examine the role of clusters in the build-up of the red sequence since z ≈ 1. In this paper, we describe the K-CLASH survey, present the sample, and provide an overview of the K-CLASH galaxy properties. We demonstrate that our sample comprises star-forming galaxies typical of their stellar masses and epochs, residing both in field and cluster environments. We conclude K-CLASH provides an ideal sample to bridge the gap between existing large integral-field spectroscopy surveys at higher and lower redshifts. We find that star-forming K-CLASH cluster galaxies at intermediate redshifts have systematically lower stellar masses than their star-forming counterparts in the field, hinting at possible “downsizing” scenarios of galaxy growth in clusters at these epochs. We measure no difference between the star-formation rates of Hα-detected, star-forming galaxies in either environment after accounting for stellar mass, suggesting that cluster quenching occurs very rapidly during the epochs probed by K-CLASH, or that star-forming K-CLASH galaxies in clusters have only recently arrived there, with insufficient time elapsed for quenching to have occured.

SDSS-IV MaNGA: the indispensable role of bars in enhancing the central star formation of low-z galaxies

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) (2020)

L Lin, C Li, C Du, E Wang, T Xiao, M Bureau, A Fraser-McKelvie, K Masters, L Lin, D Wake, L Hao

&lt;jats:title&gt;Abstract&lt;/jats:title&gt; &lt;jats:p&gt;We analyse two-dimensional maps and radial profiles of EW(H&#x3B1;), EW(H&#x3B4;A), and Dn(4000) of low-redshift galaxies using integral field spectroscopy from the MaNGA survey. Out of &#x2248;1400 nearly face-on late-type galaxies with a redshift z &amp;amp;lt; 0.05, we identify 121 &#x201C;turnover&#x201D; galaxies that each have a central upturn in EW(H&#x3B1;), EW(H&#x3B4;A) and/or a central drop in Dn(4000), indicative of ongoing/recent star formation. The turnover features are found mostly in galaxies with a stellar mass above &#x223C;1010 M&#x2299; and NUV-r colour less than &#x2248;5. The majority of the turnover galaxies are barred, with a bar fraction of 89&#xB1;3%. Furthermore, for barred galaxies the radius of the central turnover region is found to tightly correlate with one third of the bar length. Comparing the observed and the inward extrapolated star formation rate surface density, we estimate that the central SFR have been enhanced by an order of magnitude. Conversely, only half of the barred galaxies in our sample have a central turnover feature, implying that the presence of a bar is not sufficient to lead to a central SF enhancement. We further examined the SF enhancement in paired galaxies, as well as the local environment, finding no relation. This implies that environment is not a driving factor for central SF enhancement in our sample. Our results reinforce both previous findings and theoretical expectation that galactic bars play a crucial role in the secular evolution of galaxies by driving gas inflow and enhancing the star formation and bulge growth in the center.&lt;/jats:p&gt;

The 16th Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES 249 (2020) ARTN 3

The MBHBM Project - I: measurement of the central black hole mass in the Dwarf Galaxy NGC 3504 using molecular gas kinematics

Astrophysical Journal American Astronomical Society 892 (2020) 68

DD Nguyen, M den Brok, AC Seth, M Cappellari, M Bureau

We present a dynamical mass measurement of the supermassive black hole (SMBH) in the nearby double-barred spiral galaxy NGC 3504 as part of the Measuring Black Holes in below Milky Way (Msstarf) Mass Galaxies Project. Our analysis is based on Atacama Large Millimeter/submillimeter Array cycle 5 observations of the ${}^{12}\mathrm{CO}(2-1)$ emission line. These observations probe NGC 3504's circumnuclear gas disk (CND). Our dynamical model of the CND simultaneously constrains a black hole (BH) mass of ${1.6}_{-0.4}^{+0.6}\times {10}^{7}$ M⊙, which is consistent with the empirical BH–galaxy scaling relations and a mass-to-light ratio in the H band of 0.44 ± 0.12 (M⊙/${L}_{\odot }$). This measurement also relies on our new estimation of the distance to the galaxy of 32.4 ± 2.1 Mpc using the surface brightness fluctuation method, which is much further than the existing distance estimates. Additionally, our observations detect a central deficit in the ${}^{12}\mathrm{CO}(2-1)$ integrated intensity map with a diameter of 6.3 pc at the putative position of the SMBH. However, we find that a dense gas tracer CS(5 − 4) peaks at the galaxy center, filling in the 12CO(2 − 1)-attenuated hole. Holes like this one are observed in other galaxies, and our observations suggest these may be caused by changing excitation conditions rather than a true absence of molecular gas around the nucleus.

KROSS-SAMI: a direct IFS comparison of the Tully-Fisher relation across 8 Gyr since z approximate to 1

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 482 (2019) 2166-2188

AL Tiley, M Bureau, L Cortese, CM Harrison, HL Johnson, JP Stott, AM Swinbank, I Smail, D Sobral, AJ Bunker, K Glazebrook, RG Bower, D Obreschkow, JJ Bryant, MJ Jarvis, J Bland-Hawthorn, G Magdis, AM Medling, SM Sweet, C Tonini, OJ Turner, RM Sharples, SM Croom, M Goodwin, IS Konstantopoulos, NPF Lorente, JS Lawrence, J Mould, MS Owers, SN Richards

The energetics of starburst-driven outflows at z ∼ 1 from KMOS

Monthly Notices of the Royal Astronomical Society Oxford University Press 487 (2019) 381-393

AM Swinbank, CM Harrison, AL Tiley, HL Johnson, I Smail, JP Stott, PN Best, RG Bower, M Bureau, A Bunker, M Cirasuolo, M Jarvis, GE Magdis, RM Sharples, D Sobral

We present an analysis of the gas outflow energetics from KMOS observations of ∼ 529 main-sequence star-forming galaxies at z ∼ 1 using broad, underlying H α and forbidden lines of [N II] and [S II]. Based on the stacked spectra for a sample with median star-formation rates and stellar masses of SFR = 7 M⊙   yr−1 and M⋆ = (1.0 ± 0.1) × 1010 M⊙, respectively, we derive a typical mass outflow rate of M˙wind = 1–4 M⊙ yr−1 and a mass loading of M˙wind / SFR = 0.2–0.4. By comparing the kinetic energy in the wind with the energy released by supernovae, we estimate a coupling efficiency between the star formation and wind energetics of ϵ ∼  0.03. The mass loading of the wind does not show a strong trend with star-formation rate over the range ∼ 2–20 M⊙ yr−1, although we identify a trend with stellar mass such that dM / dt / SFR ∝ M0.26±0.07⋆⁠. Finally, the line width of the broad H α increases with disc circular velocity with a sub-linear scaling relation FWHMbroad ∝ v0.21 ± 0.05. As a result of this behaviour, in the lowest mass galaxies (M⋆ ≲ 1010 M⊙), a significant fraction of the outflowing gas should have sufficient velocity to escape the gravitational potential of the halo whilst in the highest mass galaxies (M⋆ ≳ 1010 M⊙) most of the gas will be retained, flowing back on to the galaxy disc at later times.

JINGLE, a JCMT legacy survey of dust and gas for galaxy evolution studies: II. SCUBA-2 850 μm data reduction and dust flux density catalogues

Monthly Notices of the Royal Astronomical Society Oxford University Press 486 (2019) 4166-4185

MWL Smith, CJR Clark, I De Looze, I Lamperti, A Saintonge, CD Wilson, G Accurso, E Brinks, M Bureau, EJ Chung, PJ Cigan, DL Clements, T Dharmawardena, L Fanciullo, Y Gao, Y Gao, WK Gear, HL Gomez, J Greenslade, HS Hwang, F Kemper, JC Lee, C Li, L Lin, L Liu

We present the SCUBA-2 850μm component of JINGLE, the new JCMT large survey for dust and gas in nearby galaxies, which with 193 galaxies is the largest targeted survey of nearby galaxies at 850 μm. We provide details of our SCUBA-2 data reduction pipeline, optimized for slightly extended sources, and including a calibration model adjusted to match conventions used in other far-infrared (FIR) data. We measure total integrated fluxes for the entire JINGLE sample in 10 infrared/submillimetre bands, including all WISE, Herschel-PACS, Herschel-SPIRE, and SCUBA-2 850 μm maps, statistically accounting for the contamination by CO(J = 3–2) in the 850 μm band. Of our initial sample of 193 galaxies, 191 are detected at 250 μm with a ≥5σ significance. In the SCUBA-2 850 μm band we detect 126 galaxies with ≥3σ significance. The distribution of the JINGLE galaxies in FIR/sub-millimetre colour–colour plots reveals that the sample is not well fit by single modified-blackbody models that assume a single dust-emissivity index (β). Instead, our new 850 μm data suggest either that a large fraction of our objects require β &lt; 1.5, or that a model allowing for an excess of sub-mm emission (e.g. a broken dust emissivity law, or a very cold dust component ≲10 K) is required. We provide relations to convert FIR colours to dust temperature and β for JINGLE-like galaxies. For JINGLE the FIR colours correlate more strongly with star-formation rate surface-density rather than the stellar surface-density, suggesting heating of dust is greater due to younger rather than older stellar-populations, consistent with the low proportion of early-type galaxies in the sample.

Dust properties in the cold and hot gas phases of the ATLAS(3D) early-type galaxies as revealed by AKARI

ASTRONOMY & ASTROPHYSICS 622 (2019) ARTN A87

T Kokusho, H Kaneda, M Bureau, T Suzuki, K Murata, A Kondo, M Yamagishi, T Tsuchikawa, T Furuta

The AGN fuelling/feedback cycle in nearby radio galaxies I. ALMA observations and early results

Monthly Notices of the Royal Astronomical Society Oxford University Press 484 (2019) 4239-4259

I Ruffa, I Prandoni, R Laing, R Paladino, P Parma, H de Ruiter, A Mignano, TA Davis, M Bureau, J Warren

This is the first paper of a series exploring the multi-frequency properties of a sample of eleven nearby low excitation radio galaxies (LERGs) in the southern sky. We are conducting an extensive study of different galaxy components (stars, warm and cold gas, radio jets) with the aim of improving our understanding of the AGN fuelling/feedback cycle in LERGs. We present ALMA Band 6 12CO(2-1) and continuum observations of nine sources. Continuum emission from the radio cores was detected in all objects. Six sources also show mm emission from jets on kpc/sub-kpc scales. The jet structures are very similar at mm and cm wavelengths. We conclude that synchrotron emission associated with the radio jets dominates the continuum spectra up to 230 GHz. The 12CO(2-1) line was detected in emission in six out of nine objects, with molecular gas masses ranging from 2 × 107 to 2 × 1010 M⊙. The CO detections show disc-like structures on scales from ≈0.2 to ≈10 kpc. In one case (NGC 3100) the CO disc presents some asymmetries and is disrupted in the direction of the northern radio jet, indicating a possible jet/disc interaction. In IC 4296, CO is detected in absorption against the radio core as well as in emission. In four of the six galaxies with CO detections, the gas rotation axes are roughly parallel to the radio jets in projection; the remaining two cases show large misalignments. In those objects where optical imaging is available, dust and CO appear to be co-spatial.

WISDOM project – IV. A molecular gas dynamical measurement of the supermassive black hole mass in NGC 524

Monthly Notices of the Royal Astronomical Society Oxford University Press 485 (2019) 4359-4374

MD Smith, M Bureau, TA Davis, M Cappellari, L Liu, EV North, K Onishi, S Iguchi, M Sarzi

We present high angular resolution (0.3 arcsec or 37 pc) Atacama Large Millimeter/submillimeter Array observations of the CO(2–1) line emission from a central disc in the early-type galaxy NGC 524. This disc is shown to be dynamically relaxed, exhibiting ordered rotation about a compact 1.3 mm continuum source, which we identify as emission from an active supermassive black hole (SMBH). There is a hole at the centre of the disc slightly larger than the SMBH sphere of influence. An azimuthal distortion of the observed velocity field is found to be due to either a position angle warp or radial gas flow over the inner 2. 5. By forward-modelling the observations, we obtain an estimate of the SMBH mass of 4.0+3.5 −2.0 × 108 M, where the uncertainties are at the 3σ level. The uncertainties are dominated by the poorly constrained inclination and the stellar mass-to-light ratio of this galaxy, and our measurement is consistent with the established correlation between SMBH mass and stellar velocity dispersion. Our result is roughly half that of the previous stellar dynamical measurement, but is consistent within the uncertainties of both. We also present and apply a new tool for modelling complex molecular gas distributions.

The shapes of the rotation curves of star-forming galaxies over the last approximate to 10 Gyr

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 485 (2019) 934-960

AL Tiley, AM Swinbank, CM Harrison, I Smail, OJ Turner, M Schaller, JP Stott, D Sobral, T Theuns, RM Sharples, S Gillman, RG Bower, AJ Bunker, P Best, J Richard, R Bacon, M Bureau, M Cirasuolo, G Magdis

SIGNALS: I. Survey description

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 489 (2019) 5530-5546

L Rousseau-Nepton, RP Martin, C Robert, L Drissen, P Amram, S Prunet, T Martin, I Moumen, A Adamo, A Alarie, P Barmby, A Boselli, F Bresolin, M Bureau, L Chemin, RC Fernandes, F Combes, C Crowder, L Della Bruna, S Duarte Puertas, F Egusa, B Epinat, VF Ksoll, M Girard, V Gómez Llanos, D Gouliermis, K Grasha, C Higgs, J Hlavacek-Larrondo, I-T Ho, J Iglesias-Páramo, G Joncas, ZS Kam, P Karera, RC Kennicutt, RS Klessen, S Lianou, L Liu, Q Liu, AL de Amorim, JD Lyman, H Martel, B Mazzilli-Ciraulo, AF McLeod, A-L Melchior, I Millan, M Mollá, R Momose, C Morisset, H-A Pan, AK Pati, A Pellerin, E Pellegrini, I Pérez, A Petric, H Plana, D Rahner, T Ruiz Lara, L Sánchez-Menguiano, K Spekkens, G Stasińska, M Takamiya, N Vale Asari, JM Vílchez

<jats:title>ABSTRACT</jats:title> <jats:p>SIGNALS, the Star formation, Ionized Gas, and Nebular Abundances Legacy Survey, is a large observing programme designed to investigate massive star formation and H ii regions in a sample of local extended galaxies. The programme will use the imaging Fourier transform spectrograph SITELLE at the Canada–France–Hawaii Telescope. Over 355 h (54.7 nights) have been allocated beginning in fall 2018 for eight consecutive semesters. Once completed, SIGNALS will provide a statistically reliable laboratory to investigate massive star formation, including over 50 000 resolved H ii regions: the largest, most complete, and homogeneous data base of spectroscopically and spatially resolved extragalactic H ii regions ever assembled. For each field observed, three datacubes covering the spectral bands of the filters SN1 (363–386 nm), SN2 (482–513 nm), and SN3 (647–685 nm) are gathered. The spectral resolution selected for each spectral band is 1000, 1000, and 5000, respectively. As defined, the project sample will facilitate the study of small-scale nebular physics and many other phenomena linked to star formation at a mean spatial resolution of ∼20 pc. This survey also has considerable legacy value for additional topics, including planetary nebulae, diffuse ionized gas, and supernova remnants. The purpose of this paper is to present a general outlook of the survey, notably the observing strategy, galaxy sample, and science requirements.</jats:p>

WISDOM project – V. Resolving molecular gas in Keplerian rotation around the supermassive black hole in NGC 0383

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 490 (2019) 319-330

EV North, TA Davis, M Bureau, M Cappellari, S Iguchi, L Liu, K Onishi, M Sarzi, MD Smith, TG Williams

<jats:title>ABSTRACT</jats:title> <jats:p>As part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM), we present a measurement of the mass of the supermassive black hole (SMBH) in the nearby early-type galaxy NGC 0383 (radio source 3C 031). This measurement is based on Atacama Large Millimeter/sub-millimeter Array (ALMA) cycle 4 and 5 observations of the 12CO(2–1) emission line with a spatial resolution of 58 × 32 pc2 (0.18 arcsec × 0.1 arcsec). This resolution, combined with a channel width of 10 km s−1, allows us to well resolve the radius of the black hole sphere of influence (measured as RSOI = 316 pc  =  0.98 arcsec), where we detect a clear Keplerian increase of the rotation velocities. NGC 0383 has a kinematically relaxed, smooth nuclear molecular gas disc with weak ring/spiral features. We forward model the ALMA data cube with the Kinematic Molecular Simulation (KinMS) tool and a Bayesian Markov Chain Monte Carlo method to measure an SMBH mass of (4.2 ± 0.7) × 109 M⊙, a F160W-band stellar mass-to-light ratio that varies from 2.8 ± 0.6 M⊙/L$_{\odot ,\, \mathrm{F160W}}$ in the centre to 2.4 ± 0.3 M⊙$/\rm L_{\odot ,\, \mathrm{F160W}}$ at the outer edge of the disc and a molecular gas velocity dispersion of 8.3 ± 2.1 km s−1(all 3σ uncertainties). We also detect unresolved continuum emission across the full bandwidth, consistent with synchrotron emission from an active galactic nucleus. This work demonstrates that low-J CO emission can resolve gas very close to the SMBH ($\approx 140\, 000$ Schwarzschild radii) and hence that the molecular gas method is highly complimentary to megamaser observations, as it can probe the same emitting material.</jats:p>

JINGLE, a JCMT legacy survey of dust and gas for galaxy evolution studies - I. Survey overview and first results

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 481 (2018) 3497-3519

A Saintonge, CD Wilson, T Xiao, L Lin, HS Hwang, T Tosaki, M Bureau, PJ Cigan, CJR Clark, DL Clements, I De Looze, T Dharmawardena, Y Gao, WK Gear, J Greenslade, I Lamperti, JC Lee, C Li, MJ Michalowski, A Mok, H-A Pan, AE Sansom, M Sargent, MWL Smith, T Williams, C Yang, M Zhu, G Accurso, P Barmby, E Brinks, N Bourne, T Brown, A Chung, EJ Chung, A Cibinel, K Coppin, J Davies, TA Davis, S Eales, L Fanciullo, T Fang, Y Gao, DHW Glass, HL Gomez, T Greve, J He, LC Ho, F Huang, H Jeong, X Jiang, Q Jiao, F Kemper, JH Kim, M Kim, T Kim, J Ko, X Kong, K Lacaille, CG Lacey, B Lee, JH Lee, W-K Lee, K Masters, S-H Oh, P Papadopoulos, C Park, S-J Park, H Parsons, K Rowlands, P Scicluna, JM Scudder, R Sethuram, S Serjeant, Y Shao, Y-K Sheen, Y Shi, H Shim, CMA Smith, K Spekkens, A-L Tsai, A Verma, S Urquhart, G Violino, S Viti, D Wake, J Wang, J Wouterloot, Y Yang, K Yim, F Yuan, Z Zheng

CO Tully-Fisher relation of star-forming galaxies at=0.05-0.3

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 479 (2018) 3319-3334

S Topal, M Bureau, AL Tiley, TA Davis, K Torii

The effects of galaxy interactions on molecular gas properties

Astrophysical Journal American Astronomical Society 868 (2018) 132

H-A Pan, L Lin, B-C Hsieh, M Bureau

Galaxy interactions are often accompanied by an enhanced star formation rate (SFR). Since molecular gas is essential for star formation, it is vital to establish whether and by how much galaxy interactions affect the molecular gas properties. We investigate the effect of interactions on global molecular gas properties by studying a sample of 58 galaxies in pairs and 154 control galaxies. Molecular gas properties are determined from observations with the JCMT, PMO, and CSO telescopes and supplemented with data from the xCOLD GASS and JINGLE surveys at 12CO(1–0) and 12CO(2–1). The SFR, gas mass (${M}_{{{\rm{H}}}_{2}}$), and gas fraction (f gas) are all enhanced in galaxies in pairs by ~2.5 times compared to the controls matched in redshift, mass, and effective radius, while the enhancement of star formation efficiency (SFE ≡SFR/${M}_{{{\rm{H}}}_{2}}$) is less than a factor of 2. We also find that the enhancements in SFR, ${M}_{{{\rm{H}}}_{2}}$ and f gas, increase with decreasing pair separation and are larger in systems with smaller stellar mass ratio. Conversely, the SFE is only enhanced in close pairs (separation &lt;20 kpc) and equal-mass systems; therefore, most galaxies in pairs lie in the same parameter space on the SFR–${M}_{{{\rm{H}}}_{2}}$ plane as controls. This is the first time that the dependence of molecular gas properties on merger configurations is probed statistically with a relatively large sample and a carefully selected control sample for individual galaxies. We conclude that galaxy interactions do modify the molecular gas properties, although the strength of the effect is dependent on merger configuration.

The KMOS Redshift One Spectroscopic Survey (KROSS): the origin of disc turbulence in z approximate to 1 star-forming galaxies

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 474 (2018) 5076-5104

HL Johnson, CM Harrison, AM Swinbank, AL Tiley, JP Stott, RG Bower, I Smail, AJ Bunker, D Sobral, OJ Turner, P Best, M Bureau, M Cirasuolo, MJ Jarvis, G Magdis, RM Sharples, J Bland-Hawthorn, B Catinella, L Cortese, SM Croom, C Federrath, K Glazebrook, SM Sweet, JJ Bryant, M Goodwin, IS Konstantopoulos, JS Lawrence, AM Medling, MS Owers, S Richards

Shape of LOSVDs in barred disks: implications for future IFU surveys

Astrophysical Journal IOP Publishing 854 (2018) 65

Z-Y Li, J Shen, M Bureau, Y Zhou, M Du, VP Debattista

The shape of LOSVDs (line-of-sight velocity distributions) carries important information about the internal dynamics of galaxies. The skewness of LOSVDs represents their asymmetric deviation from a Gaussian profile. Correlations between the skewness parameter ($h_3$) and the mean velocity ($\vm$) of a Gauss-Hermite series reflect the underlying stellar orbital configurations of different morphological components. Using two self-consistent $N$-body simulations of disk galaxies with different bar strengths, we investigate $h_3-\vm$ correlations at different inclination angles. Similar to previous studies, we find anticorrelations in the disk area, and positive correlations in the bar area when viewed edge-on. However, at intermediate inclinations, the outer parts of bars exhibit anticorrelations, while the core areas dominated by the boxy/peanut-shaped (B/PS) bulges still maintain weak positive correlations. When viewed edge-on, particles in the foreground/background disk (the wing region) in the bar area constitute the main velocity peak, whereas the particles in the bar contribute to the high-velocity tail, generating the $h_3-\vm$ correlation. If we remove the wing particles, the LOSVDs of the particles in the outer part of the bar only exhibit a low-velocity tail, resulting in a negative $h_3-\vm$ correlation, whereas the core areas in the central region still show weakly positive correlations. We discuss implications for IFU observations on bars, and show that the variation of the $h_3-\vm$ correlation in the disk galaxy may be used as a kinematic indicator of the bar and the B/PS bulge.