潮汐碎片富含HI气体,形成于相互作用和合并系统中,是研究星系外恒星形成的合适实验室。最近,几个这样的系统被观测到,其中包含了许多年轻的恒星形成区域的星系外。在以前的工作中,我们已经研究了年轻的恒星形成区域外的星系在不同的系统与光学和/或气体潮汐碎片,所有这些都与可用的档案GALEX/UV图像,以了解他们发生的频率和在哪种类型的环境。在本文中,我们寻找星系NGC 2865周围的恒星形成区,这是一个壳层星系,它被一个环的HI,与总质量为1.2 × 10 $^9$ M $_\odot$。利用双子座望远镜的多狭缝成像光谱技术,我们探测到星系NGC 2865周围的所有H $α$发射源,其通量极限为10 $^{-18}$ erg cm $^{-2}$ s $^{-1}$ erg cm $^{-1}$。再加上近和远紫外光通量信息,我们的特点,这些HII地区的恒星形成率,质量,年龄和金属丰度。我们总共在NGC 2865星系周围HI气体东南尾部的60个$\times$ 60 Kpc场中发现了26个发射线源。在26个H PDMATHAMO发射体中,有19个位于卫星星系FGCE 0745中,7个位于星系际HII区,散布在NGC 2865周围HI气体的南尾。我们发现星系际HII区域很年轻($<$ 200 Myr),恒星质量范围为4 X 10 $^3$ M $_\odot$至17 x 10 $^6$ M $_\odot$。这些都是在低HI气体密度的区域发现的,在那里形成恒星的可能性预计是低的。对于银河系间的HII区域之一,我们估计太阳氧丰度为12 + log(O/H)$\sim$ 8.7。我们还能够估计卫星星系FGCE 0745的金属丰度为12 + log(O/H)~ 8.0。
英文摘要:
Tidal debris which are rich in HI gas, formed in interacting and merging systems, are suitable laboratories to study star formation outside galaxies. Recently, several such systems were observed, which contained many young star forming regions outside the galaxies. In previous works, we have studied young star forming regions outside galaxies in different systems with optical and/or gaseous tidal debris, all of them with available archive GALEX/UV images, in order to understand how often they occur and in which type of environments. In this paper we searched for star forming regions around the galaxy NGC2865, a shell galaxy which is circled by a ring of HI, with a total mass of 1.2 x 10$^9$ M$_\odot$. Using the Multi-Slit Imaging Spectroscopy Technique with the Gemini telescope, we detected all H$α$ emitting sources in the surroundings of the galaxy NGC2865, down to a flux limit of 10$^{-18}$ erg cm$^{-2}$ s$^{-1}$ Å$^{-1}$. Together with Near and Far-Ultraviolet flux information we characterize the star formation rates, masses, ages, and metallicities for these HII regions. In total, we found 26 emission-line sources in a 60 $\times$ 60 Kpc field centered over the southeastern tail of the HI gas present around the galaxy NGC2865. Out of the 26 H$α$ emitters, 19 are in the satellite galaxy FGCE 0745 and seven are intergalactic HII regions scattered over the south tail of the HI gas around NGC2865. We found that the intergalactic HII regions are young ($<$200 Myr) with stellar masses in the range 4 X 10$^3$M$_\odot$ to 17x10$^6$ M$_\odot$. These are found in a region of low HI gas density, where the probability of forming stars is expected to be low. For one of the intergalactic HII regions we estimated a solar oxygen abundance of 12 + log(O/H) $\sim$ 8.7. We also were able to estimate the metallicity for the satellite galaxy FGCE0745 to be 12 + log(O/H) ~ 8.0.
A New Constraint on Reionization from Evolution of the Ly$α$ Luminosity Function at $z\sim6-7$ Probed by a Deep Census of $z=7.0$ Ly$α$ Emitter Candidates to 0.3 $L^*$
Tracing the earliest stages of star and cluster formation in 19 nearby galaxies with PHANGS-JWST and HST: compact 3.3 $μ$m PAH emitters and their relation to the optical census of star clusters
A Census of Double-Peaked Lyman-alpha Emitters in MAGPI: Classification, Global Characteristics, and Spatially Resolved Properties
Macquarie University(麦考瑞大学);Swinburne University of Technology(斯威本科技大学);Observatori Astronòmic de la Universitat de València(瓦伦西亚大学天文台);International Centre for Radio Astronomy Research (ICRAR), Curtin University(伊萨研究中心(ICRAR),科廷大学);Sydney Institute for Astronomy, School of Physics, University of Sydney(悉尼大学物理学院悉尼天体物理学研究所);International Centre for Radio Astronomy Research (ICRAR), The University of Western Australia(伊萨研究中心(ICRAR),西澳大学)
Probing the Metal Enrichment of the Intergalactic Medium at $z=5-6$ Using the Hubble Space Telescope
我们使用哈勃太空望远镜(HST)ACS斜坡窄带滤波器探测$z=5$ -6上四个强星系际CIV吸收体的关联星系,检验星系外流模型。四种强CIV吸收剂位于$z=5.74$、$5.52$、$4.95$和$4.87$,柱密度范围为$N_{\rm{CIV}}=10^{13.8}$ cm $^{-2}$至$10^{14.8}$ cm $^{-2}$。在$z=5.74$,我们检测到一个i-dropout Ly $α$发射体(LAE)候选者,其预计影响参数为42物理kpc,来自CIV吸收体。该LAE候选物的基于Ly $α$的恒星形成率(SFR $_{\rm{Lyα}}$)为2 $M_\odot$ yr $^{-1}$,基于UV的SFR为4 $M_\odot$ yr $^{-1}$。虽然我们不能完全排除这个$i$ -dropout发射体可能是一个[OII]闯入者,但它的测量特性与$z=5.74$的CIV动力星系一致。对于CIV吸收体在$z=4.95$和$z=4.87$,虽然我们检测到两个LAE候选人的影响参数为160 kpc和200 kpc,这样的距离大于从模拟预测。因此,我们将其视为未检测。对于在$z=5.52$的系统,我们没有检测到LAE候选,将SFR $_{\rm{Lyα}}\approx 1.5\ M_\odot$ yr $^{-1}$的3- $σ$上限。总之,在这4例病例中,我们仅在$z=…
Exploring the influence of reionisation-era galaxies on their local intergalactic medium using the Sherwood-Relics simulations
Max Planck Institut für Astrophysik(马克斯·普朗克天体物理研究所);Institute for Astronomy, University of Edinburgh(爱丁堡大学天文研究所);School of Physics and Astronomy, The University of Nottingham(诺丁汉大学物理与天文学院);Department of Astronomy, University of Michigan(密歇根大学天文学系);Leibniz-Institut für Astrophysik Potsdam(波茨坦莱布尼茨天体物理研究所)
The impact of source and survey modelling on the connection between [O III] emitters and Ly $α$ forest transmission at z ~ 6
The University of Nottingham(诺丁汉大学);University of Edinburgh(爱丁堡大学);Kavli Institute for Cosmology(卡弗里宇宙学研究所);Tata Institute of Fundamental Research(塔塔基础研究所);Leibniz-Institut für Astrophysik Potsdam(波茨坦阿斯特拉物理研究所)
The Physical Origins of the Identified and Still Missing Components of the Warm-Hot Intergalactic Medium: Insights from Deep Surveys in the Field of Blazar 1ES1553+113
星系之间的关系和温暖的热星系际介质(WHIM)预计将占主导地位的重子预算在低Z的状态/化学富集的结构形成和星系演化模型提供了敏感的约束。我们提出了一个深红移调查领域的1ES 1553 + 113,一个耀变体与一个独特的组合的UV + X射线光谱的调查环/星系间介质(CGM/IGM)。Nicastro等人在2018年报告了在其光谱中探测到两个O VII WHIM吸收体,分别位于$z=0.4339$和$0.3551$,这表明WHIM富含金属,足以解决重子缺失的问题。我们的调查表明,耀变体是一个$z=0.433$集团的成员,更高的$z$ O VII候选人产生于它的组内介质。由此产生的偏差排除了它在重子普查中的使用。$z=0.3551$的候选者发生在一个孤立的环境630千秒差距,从最近的星系(与恒星质量$\log M_*/M_\odot \approx 9.7$),我们表明是意想不到的WHIM。最后,我们描述了银河系环境的广泛H I Ly $α$吸收(多普勒宽度$b=40-80$ \kms; $T\lesssim4\times10^5$ K),提供金属丰度独立WHIM探头。平均而言,宽Ly $α$,吸收体的${\approx}2\times$比窄Ly $T\lesssim4\times10^5$($T\lesssim4\times10^5$ K)(1300 kpc)更接近最近的发光星系($…
Medium-band Astrophysics with the Grism of NIRCam In Frontier fields (MAGNIF): Spectroscopic Census of H$α$ Luminosity Functions and Cosmic Star Formation at $z\sim 4.5$ and 6.3
ESA Voyage 2050 white paper: A complete census of the gas phases in and around galaxies, far-UV spectropolarimetry as a prime tool for understanding galaxy evolution and star formation
A GLIMPSE of the 99%: a census of the faintest galaxies during the epoch of reionization and its implications for galaxy formation models
Sorbonne Université(索邦大学);The University of Texas at Austin(德克萨斯大学奥斯汀分校);Univ Lyon, Univ Lyon1, Ens de Lyon(里昂大学,里昂第一大学,巴黎高等师范学校里昂分校);University of Geneva(日内瓦大学);Tufts University(塔夫茨大学);Leiden Observatory(莱顿天文台);Space Telescope Science Institute(太空望远镜科学研究所);Rutgers University(罗格斯大学)
The Multiphase CGM in the Epoch of Reionization: CII and CIV absorbers around [OIII] Emitters
University of Trieste(的里雅斯特大学);INAF - Osservatorio Astronomico di Trieste(意大利国家天体物理研究所的里雅斯特天文台);IFPU - Institute for Fundamental Physics of the Universe(宇宙基础物理研究所);Dipartimento di Fisica “Enrico Fermi”, Università di Pisa(比萨大学恩里科·费米物理系);IUCAA(印度联合大学天体物理中心);Università degli Studi di Milano-Bicocca(米兰比可卡大学);Max-Planck-Institut für Ex
Galaxy Protoclusters as Drivers of Cosmic Reionization: II. Te-Based Metallicities of Lyman-α Emitters
Pontificia Universidad Católica de Chile(智利天主教 Pontificia 大学);Las Campanas Observatory, Carnegie Science(拉斯坎帕纳斯天文台,卡内基科学);University of California Santa Barbara(加州大学圣塔芭芭拉分校);Instituto de Astrofísica de la Facultad de Ingeniería y Ciencias, Universidad Diego Portales(迭戈·波特莱斯大学工程与科学学院天体物理研究所);Texas A&M University(德克萨斯农工大学);George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University(德克萨斯农工大学乔治·P和辛西娅·伍兹基础物理与天文学研究所);Caltech/IPAC(加州理工学院/IPAC);Institute for Cosmic Ray Research, The University of Tokyo(东京大学宇宙射线研究所);Space Telescope Science Institute(太空望远镜科学研究所)