The nearby dwarf galaxy II Zw 40 hosts an intense starburst. At the center of the starburst is a bright compact radio and infrared source, thought to be a giant dense HII region containing ~14,000 O stars. Radio continuum images suggest that the compact source is actually a collection of several smaller emission regions. We accordingly use the kinematics of the ionized gas to probe the structure of the radio-infrared emission region. With TEXES on the NASA-IRTF we measured the 10.5um [SIV] emission line with effective spectral resolutions, including thermal broadening, of ~25 and ~3 km/s and spatial resolution ~1". The line profile shows two distinct, spatially coextensive, emission features. The stronger feature is at galactic velocity and has FWHM 47 km/s. The second feature is ~44km/s redward of the first and has FWHM 32 km/s. We argue that these are two giant embedded clusters, and estimate their masses to be ~3x10^5Mo and ~1.5x10^5 Mo. The velocity shift is unexpectedly large for such a small spatial offset. We suggest that it may arise in a previously undetected kinematic feature remaining from the violent merger that formed the galaxy.
Feedback from massive stars shapes the ISM and affects the evolution of galaxies, but its mechanisms acting at the small scales ($\sim 10$ pc) are still not well constrained observationally, especially in the low-metallicity environments. We present the analysis of the ionized gas (focusing on its kinematics, which were never studied before), and its connection to the massive stars in the nearby ($D \sim 1.4$ Mpc) star-forming very metal-poor ($Z\sim 0.07 Z_\odot$) galaxy Sextans A. The analysis is based on the observations with a scanning Fabry-Perot interferometer, long-slit spectroscopy and…
Ionized Gas Kinematics at High Resolution IV: Star Formation and a Rotating Core in the Medusa (NGC 4194)
NGC 4194是一个合并后的恒星暴,因其引人注目的潮汐特征而被称为美杜莎。我们在这里提出了一个详细的研究电离气体的结构和运动学在中央0.65千秒差距的美杜莎。这些数据包括分辨率高达$0.18\arcsec$(35 pc)的射电连续谱图和光谱分辨率为$\sim4$ \kms的$12.8μ$ m [NeII]数据立方体:这是对这一非凡天体的第一次{ \it高分辨率、无干扰}观测。电离气体具有固体旋转中核心的运动学特征。星暴形成了一个明亮致密的\HII ~区域的复合体,可能是由深埋的超级星团激发的,但这些来源都不是星系核的令人信服的候选者。创造美杜莎的合并伙伴的核心尚未确定。
Ionized gas kinematics of galaxies in the CALIFA survey I: Velocity fields, kinematic parameters of the dominant component, and presence of kinematically distinct gaseous systems
Tracing kinematic (mis)alignments in CALIFA merging galaxies: Stellar and ionized gas kinematic orientations at every merger stage
我们提出了空间分辨恒星和/或电离气体的运动学性质的样本103相互作用的星系,跟踪所有合并阶段:密切的同伴,对相互作用的形态特征,合并残余物。我们将我们的样本与80个无相互作用的星系进行比较。我们测量的恒星和电离气体成分的主要(投影)的运动学位置角(PA $_{\mathrm{kin}}$,接近和后退)直接从速度场没有假设的内部运动。该方法允许我们从直线($δ$ PA $_{\mathrm{kin}}$)导出运动学PA的偏差。大约有一半的相互作用的对象显示形态运动学PA错位,不能在控制样品中找到。这些失调主要存在于具有相互作用形态特征的星系中。两个样本的运动学侧之间的对齐是相似的,大多数星系显示出小的错位。径向偏差的运动PA从一条直线的恒星组成部分测量的$δ$ PA $_{\mathrm{kin}}$是大的两个样本。然而,对于大部分的相互作用的星系的电离气体$δ$ PA $_{\mathrm{kin}}$是大于典型的孤立星系(48%)的值,使这个参数的一个很好的指标,跟踪相互作用和合并的影响,在星系的内部运动。通过比较恒星和电离气体运动学PA,我们发现42%(28/66)的相互作用星系的失调大于16度,相比之下,10%的控制样本。我们的研究结果显示了相互作用对星系内部结构的影响以及它们的速度分布的各种各样。这项研究也提供了一个本地宇宙基准的运动学研究在合并星系在高红移。
We present a spatially resolved analysis of ionized gas at the nuclear region of the nearby galaxy NGC 1068. While NGC 1068 has been known to have gas outflows driven by its active galactic nucleus (AGN), more complex kinematical signatures were recently reported, which were inconsistent with a rotation or simple biconical outflows. To account for the nature of gas kinematics, we performed a spatially resolved kinematical study, finding a morphologically symmetric pair of approaching and receding gas blobs in the northeast region. The midpoint of the two blobs is located at a distance of 180 p…
Gemini Near Infrared Field Spectrograph Observations of the Seyfert 2 Galaxy Mrk 573: In Situ Acceleration of Ionized and Molecular Gas Off Fueling Flows
我们目前的近红外和光学发射线和恒星运动学的塞弗特2星系Mrk 573使用近红外场光谱仪(NIFS)在北双子座和双成像光谱仪(DIS)在阿帕奇点天文台,分别。通过获得Mrk 573的700 x 2100 pc^2环核区域中红外电离气体和分子气体的完整运动学图以及恒星运动学图,我们发现窄线区域(NLR)内的运动学主要是由于起源于主盘的物质的旋转和原位加速的结合。结合这些观察与大规模的,光学长缝光谱,跟踪电离气体排放到几个千磅,我们发现,旋转运动学占主导地位的气体。我们发现流出的气体延伸到小于1千秒差距的距离,这表明在塞弗特星系的外流可能不足以疏散他们的整个凸起。
This study delves into the intricate kinematic behavior of ionized gas within IZw18, a galaxy known for its remarkably low metallicity and proximity. Leveraging data from MEGARA/GTC, we meticulously analyzed the galaxy's structure and dynamics using Hα line profiles. Employing single and double Gaussian component fittings, we generated detailed maps of luminosity, velocity, and velocity dispersion across both the main body (MB) and Halo regions. By extracting integrated spectra from various galactic zones, we enhanced the signal-to-noise (S/N) ratio. In the MB, a clear rotational pattern emerg…
The SDSS-IV MaNGA survey has measured two-dimensional maps of emission line velocities for a statistically powerful sample of nearby galaxies. The asymmetric features of these kinematics maps reflect the non-rotational component of a galaxy's internal motion of ionized gas. In this study, we present a catalog of kinematic asymmetry measurement of $Hα$ velocity map of a sample of 5353 MaNGA galaxies. Based on this catalog, we find that `special' galaxies (e.g. merging galaxies, barred galaxies, and AGN host galaxies) contain more galaxies with highly asymmetric velocity maps. However, we notice…
We compare dynamical mass estimates based on spatially extended stellar and ionized gas kinematics ($\mathrm{M_{dyn,*}}$ and $\mathrm{M_{dyn,eml}}$, respectively) of 157 star forming galaxies at $0.6\leq z<1$. Compared to $z\sim0$, these galaxies have enhanced star formation rates, with stellar feedback likely affecting the dynamics of the gas. We use LEGA-C DR3, the highest redshift dataset providing sufficiently deep measurements of a $K_s-$band limited sample. For $\mathrm{M_{dyn,*}}$ we use Jeans Anisotropic Multi-Gaussian Expansion models. For $\mathrm{M_{dyn,eml}}$ we first fit a custom …
[S IV] in the NGC 5253 Supernebula: Ionized Gas Kinematics at High Resolution
附近的矮恒星爆发星系NGC 5253拥有一个深深嵌入的无线电红外超星云,由数千颗O星激发。我们用IRTF上的高分辨谱仪TEXES在S+3的10.5μm谱线上以3.8kms ~(-1)的光谱分辨率和1.4”的空间分辨率观测到了这个源。线轮廓不能很好地拟合由一个单一的高斯。最佳的简单拟合用两个高斯函数来描述气体,一个接近银河系速度,半高宽为33.6 km s-1,另一个强度相似,半高宽为94 km s-1,中心距蓝方\sim 20 km s-1。这提出了一个超星云的模型,其中气体从分子云中流向我们,就像“气泡”或“香槟流”或朱(2006)模拟的HII区域。
High mass proto-stars create Ultra-Compact Hii regions (UCHII) at the stage of evolution when most of the accretion is finished but the star is still heavily embedded in molecular material. The morphologies of UCHII regions reflect the interactions of stellar winds, stellar motions, and density structure in the molecular cloud; they are complex and it has been very difficult to interpret them. We here present data obtained with TEXES on the NASA IRTF of the [NeII] emission line in the proto-cluster of young OB stars in W33 Main. The data cube has a spatial resolution of ~ 1.4 arcsec and true v…
We analyze Near-Infrared Integral Field Spectrograph (NIFS) observations of the type-2 quasar (QSO2) SDSS J094521.33+173753.2 to investigate its warm molecular and ionized gas kinematics. This QSO2 has a bolometric luminosity of 10$^{45.7}$ erg s$^{-1}$ and a redshift of z = 0.128. The K-band spectra provided by NIFS cover a range of 1.99-2.40 $μ$m where low-ionization (Pa$α$ and Br$δ$), high ionization ([S XI]$λ$1.920 $μ$m and [Si~VI]$λ$1.963 $μ$m) and warm molecular lines (from H$_2$ 1-0S(5) to 1-0S(1)) are detected, allowing us to study the multi-phase gas kinematics. Our analysis reveals g…
Kinematics of the ionized and molecular gas in nearby luminous infrared interacting galaxies
我们观测了三个相互作用的亮红外星系系统(LIRGS),其中H星系$α$是Fabry-Perot系统(GH $α$ FaS)安装在Roque de los Muchachos天文台的4.2米威廉赫歇尔望远镜上,并将观测结果与阿塔卡马大型毫米波阵列(ALMA)相结合,观测这些系统的CO排放,比较恒星形成区和分子气体云的物理性质,特别是恒星形成区的内部运动学。我们在H $α$发射数据立方体中识别了88个恒星形成区,在CO发射数据立方体中识别了27个分子云复合体。在这些系统中的恒星形成率和分子气体的表面密度显着高于在非相互作用的星系和银河系,并接近恒星形成率和分子气体的极端恒星形成星系在高红移的表面密度。速度弥散的大值也表明了气体表面密度的增强。HII区位于${\rm{SFR}}-σ_v$包膜上,因此也处于维里平衡。由于维里参数随着恒星形成速率和分子气体的表面密度而减小,我们认为这里呈现的云是重力主导的,而不是与外部压力平衡的。
Active Galactic Nuclei and STaR fOrmation in Nearby Galaxies AGNSTRONG. III. A Study on Ionized and Warm Molecular Gas Outflows of 6 Type-2 AGNs
Department of Astronomy, University of Science and Technology of China(中国科学技术大学天文系);School of Astronomy and Space Science, University of Science and Technology of China(中国科学技术大学天文与空间科学学院)
We analyze Multi Unit Spectroscopic Explorer observations of nine low-redshift (z < 0.1) Palomar-Green quasar host galaxies to investigate the spatial distribution and kinematics of the warm, ionized interstellar medium, with the goal of searching for and constraining the efficiency of active galactic nucleus (AGN) feedback. After separating the bright AGN from the starlight and nebular emission, we use pixel-wise, kpc-scale diagnostics to determine the underlying excitation mechanism of the line emission, and we measure the kinematics of the narrow-line region (NLR) to estimate the physical p…