Datasets:
ReadingTimeMachine
/
rtm-sgt-ocr-v1

Dataset card Data Studio Files Community
1
source
stringlengths
1
2.05k
⌀
target
stringlengths
1
11.7k
The cold gas mass grows via radiative cooling of the hot phase. and cold gas is converted to hot σας through the heating associated with star formation.
The cold gas mass grows via radiative cooling of the hot phase, and cold gas is converted to hot gas through the heating associated with star formation.
Stars form in the cold ISM according to a relation SFR pls
Stars form in the cold ISM according to a relation SFR $\propto \rho_{\rm cold}^{1.5}$ .
The normalisation of this relation is set in order to match the local spr|XV, relation2006b).
The normalisation of this relation is set in order to match the local $\Sigma_{\rm SFR}-\Sigma_{\rm gas}$ relation.
. Supernova pressurisation of the ISM is modeled via an "effective" equation of state2005b).
Supernova pressurisation of the ISM is modeled via an “effective” equation of state.
. Here. we assume a modest pressurisation of qgos=0.25 in the formalism.
Here, we assume a modest pressurisation of $q_{\rm EOS}=0.25$ in the formalism.
This corresponds to a mass-weighted ISM temperature of ~10K. In the Appendix we relax the star formation and equation of state assumptions in order to test the validity of our results.
This corresponds to a mass-weighted ISM temperature of $\sim10^{4.5}$ K. In the Appendix we relax the star formation and equation of state assumptions in order to test the validity of our results.
The simulations here are not cosmological: the dises are set up in an idealised manner in order to maximise spatial resolution.
The simulations here are not cosmological: the discs are set up in an idealised manner in order to maximise spatial resolution.
Here. the gravitational softening length for baryons is LOOh .. and 200h for dark matter.
Here, the gravitational softening length for baryons is 100 , and 200 for dark matter.
The disces are initialised according to the formalism. and are bulgeless.
The discs are initialised according to the formalism, and are bulgeless.
They are embedded in dark matter halos with density distributions.
They are embedded in dark matter halos with density distributions.
In order to compare with observations in a. meaningful manner. we aim to simulate galaxies comparable to those found in the local Universe.
In order to compare with observations in a meaningful manner, we aim to simulate galaxies comparable to those found in the local Universe.
Accordingly. our isolated discs are initialised inside haloes of mass ~1.91077M.;.. baryonic mass of MORSo10!Μι. circular velocity of 160ὃς and with of the baryons in the form of gas.
Accordingly, our isolated discs are initialised inside haloes of mass $\sim1.9\times 10^{12}$, baryonic mass of $\sim8\times10^{10}$, circular velocity of 160, and with of the baryons in the form of gas.
The mergers are binary 1:1 mergers between discs constructed in the same manner.
The mergers are binary 1:1 mergers between discs constructed in the same manner.
We simulate three mergers of slightly higher mass in order to ensure that they undergo a luminous starburst comparable to the most extreme ones seen in the local Universe (~100M.;vr. 1.
We simulate three mergers of slightly higher mass in order to ensure that they undergo a luminous starburst comparable to the most extreme ones seen in the local Universe $\sim100 \ \msunyrend$ ).
In particular. the dises that comprise the binary mergers have a rotation speed of 2251. halo mass of ~ M... and baryonic mass of ~2.2.10!..
In particular, the discs that comprise the binary mergers have a rotation speed of 225, halo mass of $\sim 5 \times 10^{12}$ , and baryonic mass of $\sim 2.2 \times 10^{11}$.
The mergers are set on an orbit with angles (61.64.05.05) = (30.60.- (-109.-30.71.-30) and (0.0.0.0).
The mergers are set on an orbit with angles $\theta_1,\phi_1,\theta_2,\phi_2$ ) = (30,60,-30,45), (-109,-30,71,-30) and (0,0,0,0).
The angles for the first two orbits are arbitrary. and were chosen to represent relatively "normal" orbits in our library of simulations.
The angles for the first two orbits are arbitrary, and were chosen to represent relatively “normal” orbits in our library of simulations.
The last merger is a coplanar one. and represents an extreme starburst with an extended duration. which we include simply for comparison.
The last merger is a coplanar one, and represents an extreme starburst with an extended duration, which we include simply for comparison.
We choose the first merger as our "fiducial" merger for the remainder of this paper as this particular model is well-studied in theliterature. and focus particularly on the snapshot when the star formation rate is at its peak.
We choose the first merger as our “fiducial” merger for the remainder of this paper as this particular model is well-studied in the, and focus particularly on the snapshot when the star formation rate is at its peak.
The results from all simulations are similar. and we discuss the minor differences that do exist when necessary.
The results from all simulations are similar, and we discuss the minor differences that do exist when necessary.
We assume that the entire neutral mass in a given cell is locked in a cloud which is spherical. isothermal. and of constant density.
We assume that the entire neutral mass in a given cell is locked in a cloud which is spherical, isothermal, and of constant density.
We determine the surface density of the neutral gas via
We determine the surface density of the neutral gas via
nearby cE galaxy made by the Virtual Observatory (VO) fed workflow, which became the second object of this class in the NGC 5846 group.
nearby cE galaxy made by the Virtual Observatory (VO) fed workflow, which became the second object of this class in the NGC 5846 group.
We study its internal properties using 3D-spectroscopy and datasets at different wavelength domains available in the VO and data archives.
We study its internal properties using 3D-spectroscopy and datasets at different wavelength domains available in the VO and data archives.
? describe a VO workflow constructed to search cE galaxies in nearby clusters.
\citet{Chilingarian+09} describe a VO workflow constructed to search cE galaxies in nearby clusters.
We extended it in order to detect cE candidates also in nearby groups, which would have higher extent on the sky because of smaller distances and, therefore, require different settings of theSEXTRACTOR software (?).
We extended it in order to detect cE candidates also in nearby groups, which would have higher extent on the sky because of smaller distances and, therefore, require different settings of the software \citep{BA96}.
. To test the modified workflow, we decided to use HST images of the central part of the Virgo cluster and the NGC 5846 group known to contain "legacy" cEs, NGC 4486B and NGC 58464. Surprisingly, the workflow detected a new compact object in the HST WFPC2 images of the NGC 5846 group 3.1 arcmin south-east of the group centre, which turned to have a spectrum in the Sloan Digital Sky Survey Data Release 7 (SDSS DR7, ?)), proving its membership in the group.
To test the modified workflow, we decided to use HST images of the central part of the Virgo cluster and the NGC 5846 group known to contain “legacy” cEs, NGC 4486B and NGC 5846A. Surprisingly, the workflow detected a new compact object in the HST WFPC2 images of the NGC 5846 group 3.1 arcmin south-east of the group centre, which turned to have a spectrum in the Sloan Digital Sky Survey Data Release 7 (SDSS DR7, \citealp{SDSS_DR7}) ), proving its membership in the group.
The galaxy is identified as SDSS J150634.27--013331.6, we will call it NGC 5846cE throughout the rest of theLetter.
The galaxy is identified as SDSS J150634.27+013331.6, we will call it NGC 5846cE throughout the rest of the.
. Recently, NGC 5846cE was mentioned by ? where it was classified as an UCD.
Recently, NGC 5846cE was mentioned by \citet{EZ10} where it was classified as an UCD.
The NGC 5846 group, the third massive structure in the local Universe after the Virgo and Fornax clusters, has been intensively studied in the past and, therefore, numerous complementary datasets in different wavelength domains are available in the VO.
The NGC 5846 group, the third massive structure in the local Universe after the Virgo and Fornax clusters, has been intensively studied in the past and, therefore, numerous complementary datasets in different wavelength domains are available in the VO.
The group is located at a distance of 26.1 Mpc in the Virgo III cloud of galaxies (??) corresponding to a spatial scale 126 pc arcsec! and a distance modulus 32.08 mag.
The group is located at a distance of 26.1 Mpc in the Virgo cloud of galaxies \citep{Tully82,EZ10} corresponding to a spatial scale 126 pc $^{-1}$ and a distance modulus $32.08$ mag.
We used the calibrated optical WFPC2 HST images in F555W and F814W (total integration times 2200 and 2300 sec) available from the Hubble Legacy and found by the cE search workflow to studying the internal structure of NGC 5846cE. The galaxy has a small size on the sky, therefore we used other data sources only for the integrated photometric measurements.
We used the calibrated optical WFPC2 HST images in $F555W$ and $F814W$ (total integration times 2200 and 2300 sec) available from the Hubble Legacy and found by the cE search workflow to studying the internal structure of NGC 5846cE. The galaxy has a small size on the sky, therefore we used other data sources only for the integrated photometric measurements.
All photometric data provided in this are corrected for the Galactic extinction (?)..
All photometric data provided in this are corrected for the Galactic extinction \citep{SFD98}.
The NGC 5846 group is included in the footprints of (1) the GRA Data Release of the Medium Imaging Survey (MIS) by the Galaxy Evolution Explorer (GALEX) and (2) the Data Release 6plus (DR6+) of the Large Area Survey (LAS) of the UKIRT Infrared Deep Sky Survey (UKIDSS, ?)), thus providing photometric measurements in far-UV, near-UV, and four near-IR. broadband filters YJHK in addition to the 5-band optical ugriz photometry from SDSS DR7.
The NGC 5846 group is included in the footprints of (1) the GR4 Data Release of the Medium Imaging Survey (MIS) by the Galaxy Evolution Explorer (GALEX) and (2) the Data Release 6plus (DR6+) of the Large Area Survey (LAS) of the UKIRT Infrared Deep Sky Survey (UKIDSS, \citealp{Lawrence+07}) ), thus providing photometric measurements in far-UV, near-UV, and four near-IR broadband filters $YJHK$ in addition to the 5-band optical $ugriz$ photometry from SDSS DR7.
We took Petrosian magnitudes from SDSS and UKIDSS, applying Vega-to-AB zero-point correction for the latter ones according to ?,, and total FUV and NUV magnitudes from GALEX.
We took Petrosian magnitudes from SDSS and UKIDSS, applying $AB$ zero-point correction for the latter ones according to \citet{HWLH06}, and total FUV and NUV magnitudes from GALEX.
There are publicly available archival Spitzer Space Telescope images obtained with the Infrared Array Camera (IRAC) in four photometric bands centered at 3.6, 4.5, 5.8, and 8.0 wm. We obtained total AB magnitudes of NGC 5846cE in the IRAC bands usingSEXTRACTOR and parameters).
There are publicly available archival Spitzer Space Telescope images obtained with the Infrared Array Camera (IRAC) in four photometric bands centered at 3.6, 4.5, 5.8, and 8.0 $\mu$ m. We obtained total $AB$ magnitudes of NGC 5846cE in the IRAC bands using and parameters).
Several central pixels of the galaxy image in all HST WFPC2 frames are saturated, therefore no analysis of the inner region is possible.
Several central pixels of the galaxy image in all HST WFPC2 frames are saturated, therefore no analysis of the inner region is possible.
The images were background-subtracted usingSEXTRACTOR.
The images were background-subtracted using.
Then we obtained light profiles of NGC 5846cE in both photometric bands by fitting elliptical isophotes with free orientation, ellipticity, and disky/boxy parameters using the task in the data processing environment.
Then we obtained light profiles of NGC 5846cE in both photometric bands by fitting elliptical isophotes with free orientation, ellipticity, and disky/boxy parameters using the task in the data processing environment.
In Fig 1 we present the radial behaviour of ellipticity e=1—b/a, and positional angle (top and middle panels) and the F555W—F814W colour profile.
In Fig \ref{figpaell} we present the radial behaviour of ellipticity $e = 1 - b/a$, and positional angle (top and middle panels) and the $F555W - F814W$ colour profile.
The positional angle remains stable at PA=127 deg at all radii.
The positional angle remains stable at $PA = 127$ deg at all radii.
The galaxy has very round outer isophotes (e~ 0.05) becoming significantly prolate inwards with the ellipticity reaching (e— 0.3) at r=0.125 kpc=1 arcsec.
The galaxy has very round outer isophotes $e \sim 0.05$ ) becoming significantly prolate inwards with the ellipticity reaching $e = 0.3$ ) at $r = 0.125$ $ = 1$ arcsec.
Closer to the centre the ellipticity starts to decrease, however, we could not measure it at r«0.3 arcsec due to the saturation mentioned above.
Closer to the centre the ellipticity starts to decrease, however, we could not measure it at $r<0.3$ arcsec due to the saturation mentioned above.
The radial behaviour of PA and e is identical in the two photometric bands.
The radial behaviour of $PA$ and $e$ is identical in the two photometric bands.
The isophotes remain purely elliptical without any signature of diskyness/boxiness.
The isophotes remain purely elliptical without any signature of diskyness/boxiness.
The reconstructed colour profile is completely flat having a value of F555W—F814W=0.90 mag.
The reconstructed colour profile is completely flat having a value of $F555W-F814W=0.90$ mag.
We computed a 2-dimensional colour map of NGC 5846cEapplying the Voronoi adaptive binning (?) with a
We computed a 2-dimensional colour map of NGC 5846cEapplying the Voronoi adaptive binning \citep{CC03} with a
ACDAM cosmology with (O,,.Q4.h)=(0.27.0.73.0.044.0.71) (Spergeletal...2003).
$\Lambda$ CDM cosmology with $(\Omega_{m}, \Omega_{\Lambda}, \Omega_{b}, h) =(0.27, 0.73, 0.044, 0.71)$ \citep{spergel03}.
We model the GRB allerelow source as a relativistic shell expanding into a homogeneous interstellar medium (15M) with particle number density 7 at redshift z.
We model the GRB afterglow source as a relativistic shell expanding into a homogeneous interstellar medium (ISM) with particle number density $n$ at redshift $z$.
The shell initially has an isotropic equivalent enerev £. a Lorentz [actor so. an opening hall-angle 9 and a width in the source frame eT(1-4-z)!. where we assume ,!c0 and the shell width being related to the observed GRD duration 7 (Ixobavashi.Piran.&Sari.1997).
The shell initially has an isotropic equivalent energy $E$, a Lorentz factor $\gamma_{0}$, an opening half-angle $\theta$ and a width in the source frame $c T (1+z)^{-1}$, where we assume $\gamma_{0}^{-1}<\theta$ and the shell width being related to the observed GRB duration $T$ \citep{kobayashi97}.
. The true energv is given by E;=6?E/2.
The true energy is given by $E_{j} = \theta^{2} E/2$.
Two shocks are formed: a forward shock heating the ISM and a reverse shock decelerating the shell.
Two shocks are formed: a forward shock heating the ISM and a reverse shock decelerating the shell.
At these shocks electrons are accelerated. and magnetic fields are anmplilied. leading to the svnchrotron allerelow emission.
At these shocks electrons are accelerated and magnetic fields are amplified, leading to the synchrotron afterglow emission.
We assume (hat. accelerated electrons have a power-law distribution of the Lorentz factor 54 as ολαx5,Pd, lor e>54, (ari.Piran.&Naravan1998)..
We assume that accelerated electrons have a power-law distribution of the Lorentz factor $\gamma_{e}$ as $N(\gamma_{e}) d\gamma_{e} \propto \gamma_{e}^{-p} d\gamma_{e}$ for $\gamma_{e}>\gamma_{m}$ \citep{sari98b}.
. We also assume that fractions e; (e,,) and epy (egy) Of the shock energy go into electrons and magnetic fields. respectively. at the forward (reverse) shock. where the subscripts / and r indicate the forward and reverse shock. respectively.
We also assume that fractions $\epsilon_{e,f}$ $(\epsilon_{e,r})$ and $\epsilon_{B,f}$ $(\epsilon_{B,r})$ of the shock energy go into electrons and magnetic fields, respectively, at the forward (reverse) shock, where the subscripts $f$ and $r$ indicate the forward and reverse shock, respectively.
We also assume adiabatic shocks.
We also assume adiabatic shocks.
Under the above assumptions. we can calculate (he spectra and lieht curves of the afterglows as summarized in ο,
Under the above assumptions, we can calculate the spectra and light curves of the afterglows as summarized in \ref{sec:model}.
There are 10 model parameters: E. 0. n. p. eig. €gp. €or € n . d/(19-2). but we assume e,y= for simplicity. so the actual number of parameters is 9.
There are $10$ model parameters: $E$, $\theta$, $n$, $p$, $\epsilon_{e,f}$, $\epsilon_{B,f}$, $\epsilon_{e,r}$, $\epsilon_{B,r}$ , $\gamma_{0}$ , $T/(1+z)$, but we assume $\epsilon_{e,f}=\epsilon_{e,r}$ for simplicity, so the actual number of parameters is 9.
We consider (he possible difference between (he magnetic field in the forward and reverse shocks. by using Ry=(ep,65,5)7 in equation (A23)) instead of ej). since the ejected shell may be endowed with magnetic fields from the central source Mészüros 2003)..
We consider the possible difference between the magnetic field in the forward and reverse shocks, by using ${\cal R}_{B}=(\epsilon_{B,r}/\epsilon_{B,f})^{1/2}$ in equation \ref{eq:rB}) ) instead of $\epsilon_{B,r}$, since the ejected shell may be endowed with magnetic fields from the central source \citep[e.g.,][]{zhang03b}.
We also take the sidewav expansion of the jet. (he non-relativistic regime. and the reverse shock emission into account (see ??)).
We also take the sideway expansion of the jet, the non-relativistic regime, and the reverse shock emission into account (see \ref{sec:model}) ).
In the following we examine several sets of model parameters (hat are physically motivated ab high redshilt. as summarized in Table 1..
In the following we examine several sets of model parameters that are physically motivated at high redshift, as summarized in Table \ref{tab:model}.
We estimate the maximum redshift out to which these alterglows could be detected with the VLA. LOFAR and SIXA.
We estimate the maximum redshift out to which these afterglows could be detected with the VLA, LOFAR and SKA.
We also evaluate the peak fluxes of the allerelows at the observed frequency around »~LOO MlIZ to discuss thedetectability of (he 21em absorption line later in ?? and ?7..
We also evaluate the peak fluxes of the afterglows at the observed frequency around $\nu \sim 100$ MHz to discuss thedetectability of the 21cm absorption line later in \ref{sec:z>6} and \ref{sec:z<6}. .
the clockwise disc by up to a few hundred. km/sec (which is the order of circular velocity at. these. clistances)
the clockwise disc by up to a few hundred km/sec (which is the order of circular velocity at these distances).
The velocity dispersion even in a very compact Giant. Molecular Cloud. with mass of καν 3105M. and size of 1. parsee. is only ~10 km/sec.
The velocity dispersion even in a very compact Giant Molecular Cloud, with mass of say $3\times 10^4 \msun$ and size of 1 parsec, is only $\sim 10$ km/sec.
Vhus the only way to create the observed kinematically distinct population of stars would be to postulate the existence of two or more streams (filaments) inside the cloud that pass on opposite sides of aand doοί ect completely mixed. before. forming. stars.
Thus the only way to create the observed kinematically distinct population of stars would be to postulate the existence of two or more streams (filaments) inside the cloud that pass on opposite sides of and do get completely mixed before forming stars.
Given our numerical experiments in this paper. this does not seem implausible if the cooling time is short 3%1.
Given our numerical experiments in this paper, this does not seem implausible if the cooling time is short $\beta \simlt 1$.
What is interesting in this scenario is that the massive stars of the counter-clockwise population would then have to form very quickly. Le. on a dynamical timescale. or else gaseous orbits would be mixed.
What is interesting in this scenario is that the massive stars of the counter-clockwise population would then have to form very quickly, i.e., on a dynamical timescale, or else gaseous orbits would be mixed.
Lhe rotation period. scales approximately as Lon=3000(/5""7. vears. so this is quite fast indeed.
The rotation period scales approximately as $T_{\rm rot} = 3000 (R/5'')^{3/2}$ years, so this is quite fast indeed.
1t should also be noted that recent. N-bocly simulations (??7) imply that it would have been very dillieult. for the high eccentricities and inclinations of the dynamically hotter counter-clockwise feature to have been formed. [rom a Lat. cold dise via scattering processes.
It should also be noted that recent N-body simulations \citep{Cuadra08, Alexander07} imply that it would have been very difficult for the high eccentricities and inclinations of the dynamically hotter counter-clockwise feature to have been formed from a flat, cold disc via scattering processes.
A single disc progenitor for both GC stellar features is therefore largely. ruled out.
A single disc progenitor for both GC stellar features is therefore largely ruled out.
1n contrast. in the case of the collision of two clouds as considered here. it is almost too casy to obtain an inner near- disc and a kinematically diverse stellar population farther out.
In contrast, in the case of the collision of two clouds as considered here, it is almost too easy to obtain an inner near-circular disc and a kinematically diverse stellar population farther out.
We therefore favor a model where a GMC collided. with a pre-existing cloud. or structure. such as à massive larger-scale disc. c.g.. similar to the observed €ND.
We therefore favor a model where a GMC collided with a pre-existing cloud or structure, such as a massive larger-scale disc, e.g., similar to the observed CND.
The observed. well defined. Dat. geometrically thin and near-circular/mildly. eccentric clockwise stellar svstem (?) is best. created: via a gentle accumulation of gas.
The observed well defined, flat, geometrically thin and near-circular/mildly eccentric clockwise stellar system \citep{PaumardEtal06} is best created via a gentle accumulation of gas.
Several independent major gas deposition events lead to a warped disc. and/or mixed svstems consisting of several stellar rings or cliscs co-existing at the same radius.
Several independent major gas deposition events lead to a warped disc, and/or mixed systems consisting of several stellar rings or discs co-existing at the same radius.
To avoid this happening. the inner disc must be created: on time scale longer than the critical rotation time. which is estimated at Fo~ few c107 vears.
To avoid this happening, the inner disc must be created on time scale longer than the critical rotation time, which is estimated at $t_{\rm cr} \sim$ few $\times 10^4$ years.
While these results are based on analytical arguments (7) and our simplified one-parameter -cooling model. we note that the results of 2). corroborate this as their inner stellar disc appears to be too eccentric to match the data of 7).
While these results are based on analytical arguments \citep{NC05} and our simplified one-parameter $\beta$ -cooling model, we note that the results of \cite{Bonnell08} corroborate this as their inner stellar disc appears to be too eccentric to match the data of \cite{PaumardEtal06}.
Deposition of eas in the inner disc takes place on the longest of two timescales: the cooling time foo, and the collision time. feacBafea. where A and. ο are the cloud's size and. velocity. magnitude.
Deposition of gas in the inner disc takes place on the longest of two timescales: the cooling time $t_{\rm cool}$ and the collision time, $t_{\rm coll} \sim R_{\rm cl}/v_{\rm cl}$, where $R_{\rm cl}$ and $v_{\rm cl}$ are the cloud's size and velocity magnitude.
In. the appendix we estimate the realistic cloud cooling timecollision. and show that it is always much shorter than the dynamical time unless magnetic fields are very important.
In the appendix we estimate the realistic cloud cooling time, and show that it is always much shorter than the dynamical time unless magnetic fields are very important.
We are thus left with the onlv option to require the collision itself be more prolonged than £4.
We are thus left with the only option to require the collision itself be more prolonged than $t_{\rm cr}$.
Estimating the velocity of the cloud at 04~150 km/sec. which is of order ol circular velocities in the inner Galaxy outside the inner parsec. we find £a=Rofera~10vearsF2,Lpe- Where Aa is the size of the cloud in parsecs.
Estimating the velocity of the cloud at $v_{\rm cl} \sim 150$ km/sec, which is of order of circular velocities in the inner Galaxy outside the inner parsec, we find $t_{\rm coll} = R_{\rm cl}/v_{\rm cl} \sim 10^4 \hbox{years}\; R_{\rm cl, pc}$, where $R_{\rm cl, pc}$ is the size of the cloud in parsecs.
We hence require the cloud to be larger than a few parsees to satisfy Fogzfos.
We hence require the cloud to be larger than a few parsecs to satisfy $t_{\rm coll}\simgt t_{\rm cr}$.
Note that this size is not necessarily the original size of the cloud if the cloud gets tidally disrupted before it makes the impact.
Note that this size is not necessarily the original size of the cloud if the cloud gets tidally disrupted before it makes the impact.
In the latter case we can take A.) to be the radial clistance to the centre of the Galaxy at which the tidal disruption took place.
In the latter case we can take $R_{\rm cl}$ to be the radial distance to the centre of the Galaxy at which the tidal disruption took place.
Finally. the location of the collision should. not be too far from the central parsec. or else too much angular momentum would have to be lost to deposit a significant amount of eas at 0.1 pe.
Finally, the location of the collision should not be too far from the central parsec, or else too much angular momentum would have to be lost to deposit a significant amount of gas at $\sim 0.1$ pc.
Another argument going in the same cirection comes rom a comparison of the radial distribution of gas and stars in our simulations with the observed. stellar. distribution (?)..
Another argument going in the same direction comes from a comparison of the radial distribution of gas and stars in our simulations with the observed stellar distribution \citep{PaumardEtal06}.
Phe former is too compact. ic. all of our simulations deposited: mass within the inner arcesecond.
The former is too compact, i.e., all of our simulations deposited mass within the inner arcsecond.
La aclelition. if that was indeed the case 6 million. vears ago. hen wwould have received a significant amount of fuel. enough o become at least a bright AGN.
In addition, if that was indeed the case 6 million years ago, then would have received a significant amount of fuel, enough to become at least a bright AGN.
Given the long. viscous imes in the inner areseconc. ccould actually continue to acerete this fuel now.
Given the long viscous times in the inner arcsecond, could actually continue to accrete this fuel now.
However. it is well known that there is no geometricallv thin and optically thick disc inside the inner aresecond of citepbalcke9.Naravanü2.Cuacdraüd..
However, it is well known that there is no geometrically thin and optically thick disc inside the inner arcsecond of \\citep{Falcke97,Narayan02,Cuadra04}.
Eliminating the gaseous disc by star formation is not an option as there are not enough massive voung stars observed. there.
Eliminating the gaseous disc by star formation is not an option as there are not enough massive young stars observed there.
Taking all these constraints together. we believe that the most realistic scenario would be a GALC of the order of a few parsecs in size striking the CND at the distance of a few pagsecs [romA.
Taking all these constraints together, we believe that the most realistic scenario would be a GMC of the order of a few parsecs in size striking the CND at the distance of a few parsecs from.
.. This scenario could perhaps explain the origin of the inner edge of the CND at /?z2 pe if the refilling time scale is longer than the age of the voung stars.
This scenario could perhaps explain the origin of the inner edge of the CND at $R\approx2$ pc if the refilling time scale is longer than the age of the young stars.
Alternatively such a cloud. could. self-collide if the impact parameter with respect to iis small enough. but the cloud. needs to be very structured. c.g. essentially consist of several smaller clouds or filaments.
Alternatively such a cloud could self-collide if the impact parameter with respect to is small enough, but the cloud needs to be very structured, e.g., essentially consist of several smaller clouds or filaments.
In this paper we presented: several simulations. of cloud-cloud collisions aimed at reproducing gas flows that could have formed (a) gaseous disc(s) in the central parsee of our Galaxy. as well as the resulting star formation.
In this paper we presented several simulations of cloud-cloud collisions aimed at reproducing gas flows that could have formed (a) gaseous disc(s) in the central parsec of our Galaxy, as well as the resulting star formation.
We found the gas cooling time and the impact parameter of the collision to inlluence the outcome significantly.
We found the gas cooling time and the impact parameter of the collision to influence the outcome significantly.
Nevertheless. there are several robust results: (a) the inner near-circular and outer eccentric orbital structure of the stars formed. there: (b) a sharply peakecl mass distribution of stars V,(R)~ l/H7: (0) that the gaseous. and stellar discs are warped.
Nevertheless, there are several robust results: (a) the inner near-circular and outer eccentric orbital structure of the stars formed there; (b) a sharply peaked mass distribution of stars $\Sigma_*(R) \sim 1/R^2$ ; (c) that the gaseous and stellar discs are warped.
‘These results are in good accordance with the observations.
These results are in good accordance with the observations.
The breakdown of the stellar system into one or more components is sensitive to the initial conditions and. also the cooling parameter.
The breakdown of the stellar system into one or more components is sensitive to the initial conditions and also the cooling parameter.
]t appears that a GAIC with a size of one to a few parsees. self-colliding on a nearly radial orbit. or striking the CND at the cistanee of a few parsec from ccould. explain the known observational data satisfactorily.
It appears that a GMC with a size of one to a few parsecs, self-colliding on a nearly radial orbit, or striking the CND at the distance of a few parsec from could explain the known observational data satisfactorily.