Optical studies of starbursts, AGN and their connections usually leave out galaxies whose emission lines are too weak to warrant reliable measurement and classification. Yet, weak line galaxies abound, and deserve a closer look. We show that these galaxies are either massive, metal rich star-forming systems, or, more often, LINERs. From our detailed stellar population analysis, we find that these LINERs have stopped forming stars long ago. Moreover, their ionizing radiation field is amazingly consistent with that expected from their old stellar populations alone. The black-hole in the centers of these massive, early-type galaxies is not active enough to overwhelm stellar ionization, and thus, despite their looks, they should not be called AGN.
Propagation of fast-mode magneto-hydrodynamic (MHD) compression waves is traced in the Galactic Centre. MHD waves produced by the active Galactic nucleus (Sgr A) focus on the molecular clouds such as Sgr B in the central molecular zone, which will trigger star formation, or possibly starburst. MHD waves newly excited by the starburst propagate backward, and focus on the nucleus (Sgr A), where implosive waves compress the nuclear gas to promote fueling the nucleus and may trigger nucleus activity. Echoing focusing of MHD waves between Sgr A (active galactic nucleus: AGN) and Sgr B (starburst) t…
We conduct for the first time a theoretical investigation of the mid-infrared spectral energy distribution (SED) produced by dust heated by an active galactic nucleus (AGN) and an extreme starburst. These models employ an integrated modeling approach using photoionization and stellar population synthesis models in which both the line and emergent continuum is predicted from gas exposed to the ionizing radiation from a young starburst and an AGN. In this work, we focus on the infrared colors from the {\it Wide-field Infrared Survey Explorer}, predicting the dependence of the colors on the input…
Post starburst E+A galaxies show indications of a powerful starburst that was quenched abruptly. Their disturbed, bulge-dominated morphologies suggest that they are merger remnants. The more massive E+A galaxies are suggested to be quenched by AGN feedback, yet little is known about AGN-driven winds in this short-lived phase. We present spatially-resolved IFU spectroscopy by the Keck Cosmic Web Imager of SDSS J003443.68+251020.9, at z=0.118. The system consists of two galaxies, the larger of which is a post starburst E+A galaxy hosting an AGN. Our modelling suggests a 400 Myrs starburst, with …
Extreme MgII Emission in Recently-Quenched Galaxies: A New Sample of Intermediate-Redshift Post-Starburst Quasars from the DESI Early Data Release
University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）；The Johns Hopkins University（约翰斯·霍普金斯大学）；Princeton University（普林斯顿大学）；University of Nottingham（诺丁汉大学）；Space Telescope Science Institute（太空望远镜科学研究所）
Sparks II: Panchromatic SED modeling and galaxy physical properties across the starburst to post-starburst sequence
Kavli Institute for Particle Astrophysics & Cosmology, Stanford University（斯坦福大学卡弗里粒子天体物理与宇宙学研究所）；Center for Decoding the Universe, Stanford University（斯坦福大学解码宇宙中心）；Department of Astrophysical Sciences, Princeton University（普林斯顿大学天体物理科学系）；Department of Astronomy and Astrophysics, University of California Santa Cruz（加州大学圣克鲁兹分校天文与天体物理系）；Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU)（宇宙物理与数学卡弗里研究所）；Division of Science, National Astronomical Observatory of Japan（日本国立天文台科学部）；Max-Planck-Institut für extraterrestrische Physik（马克斯·普朗克地外物理学研究所）
E+A galaxies are believed to be a short phase connecting major merger ULIRGs with red and dead elliptical galaxies. Their optical spectrum suggests a massive starburst that was quenched abruptly, and their bulge-dominated morphologies with tidal tails suggest that they are merger remnants. AGN-driven winds are believed to be one of the processes responsible for the sudden quenching of star formation and for the expulsion and/or destruction of the remaining molecular gas. Little is known about AGN-driven winds in this short-lived phase. In this paper we present the first and unique sample of po…
A Multiwavelength Evaluation of AGN in the Post-Starburst Phase
Johns Hopkins University（约翰斯·霍普金斯大学）；Texas A&M University（德克萨斯农工大学）；Space Telescope Science Institute（太空望远镜科学研究所）；AURA for ESA（欧洲空间局天文研究协调协会）；The College of New Jersey（新泽西学院）；Arizona State University（亚利桑那州立大学）；University of Waterloo（滑铁卢大学）
We demonstrate a robust method of resolving the star-formation and AGN contributions to emission lines using two very well known AGN systems: NGC 1365, and NGC 1068, using the high spatial resolution data from the TYPHOON/PrISM survey. We expand the previous method of calculating the AGN fraction by using theoretical-based model grids rather than empirical points. The high spatial resolution of the TYPHOON/PrISM observations show evidence of both star formation and AGN activity occurring in the nuclei of the two galaxies. We rebin the data to the lower resolutions, typically found in other int…
Comparison of AGN and Nuclear Starburst Activity in Seyfert 1 and 2 Galaxies over a Wide Luminosity Range Based on Near-infrared 2-4 micrometer Spectroscopy
Sparks: The Magellan/FIRE survey from starburst to post-starburst
Kavli Institute for Particle Astrophysics & Cosmology, Stanford University（斯坦福大学卡弗里粒子天体物理与宇宙学研究所）；Center for Decoding the Universe, Stanford University（斯坦福大学解码宇宙中心）；Department of Astrophysical Sciences, Princeton University（普林斯顿大学天体物理科学系）；Department of Astronomy and Astrophysics, University of California Santa Cruz（加州大学圣克鲁兹分校天文与天体物理系）；Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU)（宇宙物理与数学卡弗里研究所）；Division of Science, National Astronomical Observatory of Japan（日本国立天文台科学部）；Department of Physics and Astronomy, University of California, Riverside（加州大学河滨分校物理与天文系）；Max-Planck-Institut für extraterrestrische Physik（马克斯·普朗克地外物理研究所）
We have modelled the line ratios and the continuum spectral energy distribution (SED) of the short gamma-ray burst GRB100628A host galaxy complex. The results suggest that an active galactic nucleus (AGN) and a star-burst (SB) coexist in Nicuesa Guelbenzu et al.'s 'galaxy C'. The AGN spectrum is explained by a relatively strong flux. Two of the observed regions (blobs) are located in the ISM, outside the AGN photoionization cones. The strongest Hb line flux calculated by a SB dominated model was found in the tidal tail of galaxy C, while the strongest Hb line flux calculated by an AGN dominate…
We infer and compare the specific X-ray luminosity distributions for a sample of massive (i.e. $\log_{10} (M*/M\odot) > 10.5$) galaxies split according to their far-infrared-derived star-forming properties (i.e., starburst and non-starburst) and redshift. We model each distribution as a power-law with an upper and lower turnover, and adopt a maximum likelihood method to include information from non-detections in the form of upper limits. When we use our inferred distributions to calculate the ratios of high to low sLx AGN (corresponding to above and below $0.1λ_{\text{Edd}}$, respectively) we …
This work uses multiscale environments and structures of galaxies in the Sloan Digital Sky Survey as consistency checks of the evolution from starburst to quiescence at redshift $z < 0.2$. The environmental indicators include fixed aperture mass overdensities ($δ_{x\mathrm{Mpc}}$, $x \in \{0.5, 1, 2, 4, 8\}\,h^{-1}$Mpc), $k$-nearest neighbor distances, the tidal parameter, halo mass ($M_h$), and satellite/central classification. The residuals of specific star formation rates ($Δ\,\mathrm{SSFR}$) is used to select starbursts ($Δ\,\mathrm{SSFR} > 0.6\,$dex, $N \approx 8,\,600$). Quenched post-st…
Galactic outflows can be powered either by nuclear starbursts (SB) or active galactic nuclei (AGN). It has been argued that extreme starbursts can power extreme outflows, without the need to invoke AGN feedback. However, contributions from past and/or hidden AGN activity cannot be ruled out. Here, we constrain the potential role of the central black hole in driving powerful outflows in starburst galaxies (with no sign of ongoing AGN activity). We examine whether the galactic outflows can be explained by AGN luminosity evolution in the framework of our AGN `radiative dusty feedback' scenario. W…
The Starburst-AGN connection: quenching the fire and feeding the beast
两个旋涡星系的合并被认为是产生椭圆星系和早型星系的主要途径之一。在这个过程中，该系统变成了一个（超）亮红外星系，或（U）LIRG，它会演变成类星体，K+A星系，最后变成早期星系。这一变化的时间尺度仅受观测的松散约束。特别地，K+A阶段应该紧随类星体阶段之后，在此期间，（U）LIRG阶段剩余的尘埃和气体被AGN排出。具有K+A光谱特征的类星体的中间类别，星暴后类星体或PSQ，可能代表类星体和K+ A之间的过渡阶段。我们从SDSS DR 7类星体目录中收集了72个$z<0.5$ PSQ样本。我们发现，在这个样本中的中间年龄人口平均显着较弱，比他们的假定的后代，K+A星系的金属贫乏。PSQ的典型的光谱能量分布是很好地拟合由三个组件：星光;一个模糊的幂律;和一个热的尘埃组件所需的重现中红外通量。从斜率和测辐射热光度的幂律分量，我们估计典型的质量和吸积率的活动星系核，但我们发现在我们的样品中的强大的无线电大声或强X射线发射器的证据很少。这可能表明，幂律成分起源于核恒星暴，而不是活动星系核，如果它们的大部分年轻恒星仍在形成，或者活动星系核仍然被尘埃和气体严重笼罩。我们发现，这两种选择都是有问题的，需要更多更好的光学，X射线和毫米波观测来阐明PSQ的进化历史。
We report molecular gas observations of IRAS 20100-4156 and IRAS 03158+4227, two local ultraluminous infrared galaxies (ULIRGs) hosting some of the fastest and most massive molecular outflows known. Using ALMA and PdBI observations, we spatially resolve the CO(1-0) emission from the outflowing molecular gas in both and find maximum outflow velocities of $ v_{\rm max} \sim 1600$ and $\sim 1700$ km/s for IRAS 20100-4156 and IRAS 03158+4227, respectively. We find total gas mass outflow rates of $\dot M_{\rm OF} \sim 670$ and $\sim 350$ Msun/yr, respectively, corresponding to molecular gas depleti…
We investigate a sample of 152 dusty sources at 1:5 < z < 2:5 to understand the connection of enhanced Star-Formation-Rate (SFR) and Black-Hole-Accretion-Rate (BHAR). The sources are Herschel-selected, having stellar masses M*>10^10Msun and SFR (100-1000Msun/yr) elevated(>4?) above the star-forming "main sequence", classifying them as Starbursts (SB). Through a multiwavelength fitting approach (including a dusty torus component), we divided the sample into active SBs (dominated by an AGN emission, SBs-AGN, ? 23% of the sample) and purely star-forming SBs (SBs-SFR). We visually inspected their …
Post starburst E+A galaxies are systems that hosted a powerful starburst that was quenched abruptly. Simulations suggest that these systems provide the missing link between major merger ULIRGs and red and dead ellipticals, where AGN feedback is responsible for the expulsion or destruction of the molecular gas. However, many details remain unresolved and little is known about AGN-driven winds in this short-lived phase. We present spatially-resolved IFU spectroscopy with MUSE/VLT of SDSS J124754.95-033738.6, a post starburst E+A galaxy with a recent starburst that started 70 Myrs ago and ended 3…
We present the discovery of a small kinematically decoupled core of 0.2$^{\prime\prime}$ (60 pc) in radius as well as an outflow jet in the archetypical AGN-starburst "composite" galaxy NGC 7130 from integral field data obtained with the adaptive optics-assisted MUSE-NFM instrument on the VLT. Correcting the already good natural seeing at the time of our science verification observations with the four-laser GALACSI AO system, we reach an unprecedented spatial resolution at optical wavelengths of around 0.15$^{\prime\prime}$. We confirm the existence of star-forming knots arranged in a ring of …
Starburst galaxies are huge reservoirs of cosmic rays (CRs) and these CRs convert a significant fraction of their energy into gamma-rays by colliding with the interstellar medium (ISM). The produced GeV gamma-ray emission is temporally stable and the flux is found to correlate well with indicators of star formation rates, such as the total infrared (IR) luminosity $L_{\rm IR}$ and monochromatic radio continuum luminosity at 1.4 GHz $L_{\rm 1.4\ GHz}$, i.e., following $L_γ-L_{\rm IR}$ and $L_γ-L_{\rm 1.4\ GHz}$ relations. Recently, gamma-ray excesses are reported to be spatially coincident with…
We discuss the possible origin of the double-peaked profiles recently observed in Lyman-Alpha Emitters (LAEs) at the epoch of reionization ($z \gtrsim 6.5$) from obscured active galactic nuclei (AGN). Combining the extent of the Lyman-$α$ near-zones estimated from the blue peak velocity offset in these galaxies, with the ionizing emissivity of quasars at $z \gtrsim 6$, we forecast the intrinsic UV and X-ray luminosities of the AGN needed to give rise to their double-peaked profiles. We also estimate the extent of the obscuration of the AGN by comparing their luminosities to those of similar qu…
The Cosmic Owl: Twin Active Collisional Ring Galaxies with Starburst Merging Front at $z=1.14$
Tsinghua University（清华大学）；National Radio Astronomy Observatory（国家射电天文台）；The University of Tokyo（东京大学）；Kavli Institute for the Physics and Mathematics of the Universe (WPI)（宇宙物理与数学研究 Kavli 研究所（WPI））；Center for Data-Driven Discovery, Kavli IPMU (WPI), UTIAS（数据驱动发现中心，Kavli IPMU（WPI），UTIAS）；Aix Marseille Univ.（艾克斯马赛大学）；CNRS（法国国家科学研究中心）；CNES（法国国家空间研究中心）；LAM（拉格朗日天体物理学实验室）；European Southern Observatory（欧洲南方天文台）
The mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) is probing supermassive black holes (SMBHs) in galaxies across the Hubble sequence via molecular gas dynamics. We present the first WISDOM study of a luminous infrared galaxy with an active galactic nuclei (AGN): Fairall 49. We use new ALMA observations of the CO(2-1) line with a spatial resolution of about 80 pc together with ancillary HST imaging. We reach the following results: (1) The CO kinematics are well described by a regularly rotating gas disk with a radial inflow motion, suggesting weak feedback on the cold gas from b…
HATLAS J084933.4+021443 was identified as a dusty starburst via its rest-frame far-IR emission. Multi-frequency imaging and spectroscopy revealed a cluster of four dusty galaxies at $z = 2.41$, covering 80 kpc. Here, we use ALMA to confirm a more distant, fifth protocluster member, and present X-ray and rest-frame optical imaging spectroscopy of the brightest, an unlensed hyperluminous IR galaxy (HyLIRG). The data reveal broad H αand bright [N II] lines, and bright X-ray emission, characteristics that betray a Type-1 active galactic nucleus (AGN), strengthening evidence that AGN are ubiquitous…
