ترغب بنشر مسار تعليمي؟ اضغط هنا

GMOS-IFU Spectroscopy of 167-317 (LV2) Proplyd in Orion

90   0   0.0 ( 0 )
 نشر من قبل Maria Jaqueline Vasconcelos
 تاريخ النشر 2005
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

We present high spatial resolution spectroscopic observations of the proplyd 167-317 (LV2) near the Trapezium cluster in the Orion nebula, obtained during the System Verification run of the Gemini Multi Object Spectrograph (GMOS) Integral Field Unit (IFU) at the Gemini South Observatory. We have detected 38 forbidden and permitted emission lines associated with the proplyd and its redshifted jet. We have been able to detect three velocity components in the profiles of some of these lines: a peak with a 28-33 km/s systemic velocity that is associated with the photoevaporated proplyd flow, a highly redshifted component associated with a previously reported jet (which has receding velocities of about 80-120 km/s with respect to the systemic velocity and is spatially distributed to the southeast of the proplyd) and a less obvious, approaching structure, which may possibly be associated with a faint counter-jet with systemic velocity of (-75 +/- 15) km/s. We find evidences that the redshifted jet has a variable velocity, with slow fluctuations as a function of the distance from the proplyd. We present several background subtracted, spatially distributed emission line maps and we use this information to obtain the dynamical characteristics over the observed field. Using a simple model and with the extinction corrected Halpha fluxes, we estimate the mass loss rate for both the proplyd photoevaporated flow and the redshifted microjet, obtaining (6.2 +/- 0.6) x 10^{-7} M_sun/year and (2.0 +/- 0.7) x 10^{-8} M_sun/year, respectively.

قيم البحث

اقرأ أيضاً

New results of a Programme of study of BAL + IR + Fe II QSOs (at low and high redshift) are presented. Which are based mainly on deep Gemini GMOS integral field unit (IFU/3D) spectroscopy. We have performed a detailed study of the kinematics, morphol ogical, and physical conditions, in the BAL + IR + Fe II QSO: IRAS 04505-2958. From this study, some selected results are presented, mainly for the 3 expanding giant shells (observed with Gemini). In particular, the GMOS data suggest that the outflow (OF) process -in this IR QSO- generated multiple expanding hypergiant shells (from 10, to 100 kpc), in several extreme explosive events. These new Gemini GMOS data are in good agreement with our evolutionary, explosive and composite Model: where part of the ISM of the host galaxy is ejected in the form of multiple giant shells, mainly by HyN explosions. This process could generate satellite/companion galaxies, and even could expel a high fraction -or all- the host galaxy. In addition, this Model for AGN could give important clue about the physical processes that could explain the origin -in AGNs- of very energetic cosmic rays, detected by the P. Auger Observatory.
We present new high resolution spectroscopic observations of the Herbig-Haro object HH 32 from System Verification observations made with the GMOS IFU at Gemini North Observatory. The 3D spectral data covers a 8.7 x 5.85 spatial field and 4820 - 7040 Angstrom spectral region centered on the HH~32 A knot complex. We show the position-dependent line profiles and radial velocity channel maps of the Halpha line, as well as line ratio velocity channel maps of [OIII]5007/Halpha, [OI]6300/Halpha, [NII]6583/Halpha, [SII](6716+6730)/Halpha and [SII]6716/6730. We find that the line emission and the line ratios vary significantly on spatial scales of ~1 and over velocities of ~50 km/s. A ``3/2-D bow shock model is qualitatively successful at reproducing the general features of the radial velocity channel maps, but it does not show the same complexity as the data and it fails to reproduce the line ratios in our high spatial resolution maps. The observations of HH 32 A show two or three superimposed bow shocks with separations of ~3, which we interpret as evidence of a line of sight superposition of two or three working surfaces located along the redshifted body of the HH 32 outflow.
We analyse optical datacubes of the inner kiloparsec of 30 local ($zle0.02$) active galactic nuclei (AGN) hosts that our research group, AGNIFS, has collected over the past decade via observations with the integral field units of the Gemini Multi-Obj ect Spectrographs. Spatial resolutions range between $50~{rm pc}$ and $300~{rm pc}$ and spectral coverage is from $4800~mathring{A}$ or $5600~mathring{A}$ to $7000~mathring{A}$, at velocity resolutions of $approx 50~{rm km~s^{-1}}$. We derive maps of the gas excitation and kinematics, determine the AGN ionisation axis -- which has random orientation relative to the galaxy, and the kinematic major axes of the emitting gas. We find that rotation dominates the gas kinematics in most cases, but is disturbed by the presence of inflows and outflows. Outflows have been found in 21 nuclei, usually along the ionisation axis. The gas velocity dispersion is traced by $W_{80}$ (velocity width encompassing 80 per cent of the line flux), adopted as a tracer of outflows. In 7 sources $W_{80}$ is enhanced perpendicularly to the ionisation axis, indicating lateral expansion of the outflow. We have estimated mass-outflow rates $dot{M}$ and powers $dot{E}$, finding median values of $log,[dot{M}/({rm,M_odot,yr^{-1}})]=-2.1_{-1.0}^{+1.6}$ and $log,[dot{E}/({rm,erg,s^{-1}})]=38.5_{-0.9}^{+1.8}$, respectively. Both quantities show a mild correlation with the AGN luminosity ($L_{rm AGN}$). $dot{E}$ is of the order of 0.01 $L_{rm AGN}$ for 4 sources, but much lower for the majority (9) of the sources, with a median value of $log,[dot{E}/L_{rm AGN}]=-5.34_{-0.9}^{+3.2}$ indicating that typical outflows in the local Universe are unlikely to significantly impact their host galaxy evolution.
345 - M. F. Graham 2002
Presented here are high angular resolution MERLIN 5 GHz (6 cm) continuum observations of the binary proplyd system, LV 1 in the Orion nebula, which consists of proplyd 168--326SE and its binary proplyd companion 168--326NW (separation 0.4 arcsec). Ac curate astrometric alignment allows a detailed comparison between these data and published HST PC Halpha and [Oiii] images. Thermal radio sources coincide with the two proplyds and originate in the ionized photoevaporating flows seen in the optical emission lines. Flow velocities of approx 50 km/s from the ionized proplyd surfaces and geq 100 km/s from a possible micro-jet have been detected using the Manchester Echelle spectrometer. A third radio source is found to coincide with a region of extended, high excitation, optical line emission that lies between the binary proplyds 168--326SE/326NW . This is modelled as a bowshock due to the collision of the photoevaporating flows from the two proplyds. Both a thermal and a non-thermal origin for the radio emission in this collision zone are considered.
We present two-dimensional stellar and gaseous kinematics of the inner 0.7 $times$ 1.2 kpc$^{2}$ of the Seyfert galaxy ESO 362-G18, derived from optical spectra obtained with the GMOS/IFU on the Gemini South telescope at a spatial resolution of $appr ox$170 pc and spectral resolution of 36 km s$^{-1}$. ESO 362-G18 is a strongly perturbed galaxy of morphological type Sa or S0/a, with a minor merger approaching along the NE direction. Previous studies have shown that the [OIII] emission shows a fan-shaped extension of $approx$ 10arcsec to the SE. We detect the [OIII] doublet, [NII] and H${alpha}$ emission lines throughout our field of view. The stellar kinematics is dominated by circular motions in the galaxy plane, with a kinematic position angle of $approx$137$^{circ}$. The gas kinematics is also dominated by rotation, with kinematic position angles ranging from 122$^{circ}$ to 139$^{circ}$. A double-Gaussian fit to the [OIII]$lambda$5007 and H${alpha}$ lines, which have the highest signal to noise ratios of the emission lines, reveal two kinematic components: (1) a component at lower radial velocities which we interpret as gas rotating in the galactic disk; and (2) a component with line of sight velocities 100-250 km s$^{-1}$ higher than the systemic velocity, interpreted as originating in the outflowing gas within the AGN ionization cone. We estimate a mass outflow rate of 7.4 $times$ 10$^{-2}$ M$_{odot}$ yr$^{-1}$ in the SE ionization cone (this rate doubles if we assume a biconical configuration), and a mass accretion rate on the supermassive black hole (SMBH) of 2.2 $times$ 10$^{-2}$ M$_{odot}$ yr$^{-1}$. The total ionized gas mass within $sim$84 pc of the nucleus is 3.3 $times$ 10$^{5}$ M$_{odot}$; infall velocities of $sim$34 km s$^{-1}$ in this gas would be required to feed both the outflow and SMBH accretion.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا