ترغب بنشر مسار تعليمي؟ اضغط هنا

Early Science with the Large Millimeter Telescope: an energy-driven wind revealed by massive molecular and fast X-ray outflows in the Seyfert Galaxy IRAS 17020+4544

241   0   0.0 ( 0 )
 نشر من قبل Anna Lia Longinotti
 تاريخ النشر 2018
  مجال البحث فيزياء
والبحث باللغة English
 تأليف A.L. Longinotti




اسأل ChatGPT حول البحث

We report on the coexistence of powerful gas outflows observed in millimeter and X-ray data of the Radio-Loud Narrow Line Seyfert 1 Galaxy IRAS 17020+4544. Thanks to the large collecting power of the Large Millimeter Telescope, a prominent line arising from the 12CO(1-0) transition was revealed in recent observations of this source. The complex profile is composed by a narrow double-peak line and a broad wing. While the double-peak structure may be arising in a disk of molecular material, the broad wing is interpreted as the signature of a massive outflow of molecular gas with an approximate bulk velocity of -660 km/s. This molecular wind is likely associated to a multi-component X-ray Ultra-Fast Outflow with velocities reaching up to ~0.1c and column densities in the range 10^{21-23.9} cm^-2 that was reported in the source prior to the LMT observations. The momentum load estimated in the two gas phases indicates that within the observational uncertainties the outflow is consistent with being propagating through the galaxy and sweeping up the gas while conserving its energy. This scenario, which has been often postulated as a viable mechanism of how AGN feedback takes place, has so far been observed only in ULIRGs sources. IRAS 17020+4544 with bolometric and infrared luminosity respectively of 5X10^{44} erg/s and 1.05X10^{11} L_sun appears to be an example of AGN feedback in a NLSy1 Galaxy (a low power AGN). New proprietary multi-wavelength data recently obtained on this source will allow us to corroborate the proposed hypothesis.

قيم البحث

اقرأ أيضاً

112 - A. G. Gonzalez 2020
We present results of temporal and spectral analyses on four XMM-Newton EPIC pn observations of IRAS 17020+4544, a narrow-line Seyfert 1 galaxy with evidence of a radio jet. Analysis of the light curves reveals that this radio-loud source does not be have like the bulk population of its radio-quiet counterparts. A trend of spectral hardening with increased flux is found. Variability is found to increase with energy, though it decreases as the spectrum hardens. The first 40 ks of the most recent observation behave uniquely among the epochs, exhibiting a softer spectral state than at any other time. Possible non-stationarity at low energies is found, with no such effect present at higher energies, suggesting at least two distinct spectral components. A reverberation signature is confirmed, with the lag-frequency, lag-energy, and covariance spectra changing significantly during the soft-state epoch. The temporal analysis suggests a variable power-law in the presence of a reflection component, thus motivating such a fit for the 0.3-10 keV EPIC pn spectra from all epochs. We find an acceptable spectral fit using the timing-motivated parameters and report the detection of a broad Fe K emission line, requiring an additional model component beyond the reflection spectrum. We discuss links between this source and other narrow-line Seyfert 1 sources that show evidence of jet activity, finding similarities among this currently very limited sample of interesting objects.
We present ALMA observations of the inner 1 (1.2 kpc) of the Circinus galaxy, the nearest Seyfert. We target CO (1-0) in the region associated with a well-known multiphase outflow driven by the central active galactic nucleus (AGN). While the geometr y of Circinus and its outflow make disentangling the latter difficult, we see indications of outflowing molecular gas at velocities consistent with the ionized outflow. We constrain the mass of the outflowing molecular gas to be 1.5e5 -5.1e6 solar masses, yielding a molecular outflow rate of 0.35-12.3 solar masses per year. The values within this range are comparable to the star formation rate in Circinus, indicating that the outflow indeed regulates star formation to some degree. The molecular outflow in Circinus is considerably lower in mass and energetics than previously-studied AGN-driven outflows, especially given its high ratio of AGN luminosity to bolometric luminosity. The molecular outflow in Circinus is, however, consistent with some trends put forth in Cicone et al. (2014), including a linear relation between kinetic power and AGN luminosity, as well as its momentum rate vs. bolometric luminosity (although the latter places Circinus among the starburst galaxies in that sample). We detect additional molecular species including CN and C17O.
Sensitive, imaging observations of the 1.1 mm dust continuum emission from a 1 deg^2 area collected with the AzTEC bolometer camera on the Large Millimeter Telescope are presented. A catalog of 1545 compact sources is constructed based on a Wiener-op timization filter. These sources are linked to larger clump structures identified in the Bolocam Galactic Plane Survey. Hydrogen column densities are calculated for all sources and mass and mean volume densities are derived for the subset of sources for which kinematic distances can be assigned. The AzTEC sources are localized, high density peaks within the massive clumps of molecular clouds and comprise 5-15% of the clump mass. We examine the role of the gravitational instability in generating these fragments by comparing the mass of embedded AzTEC sources to the Jeans mass of the parent BGPS object. For sources with distances less than 6 kpc the fragment masses are comparable to the clump Jeans mass, despite having isothermal Mach numbers between 1.6 and 7.2. AzTEC sources linked to ultra-compact HII regions have mass surface densities greater than the critical value implied by the mass-size relationship of infrared dark clouds with high mass star formation while AzTEC sources associated with Class II methanol masers have mass surface densities greater than 0.7 g cm^{-2} that approaches the proposed threshold required to form massive stars.
We report an early science discovery of the CO(1-0) emission line in the collisional ring galaxy, VII Zw466, using the Redshift Search Receiver instrument on the Large Millimeter Telescope Alfonso Serrano.The apparent molecular-to-atomic gas ratio ei ther places the ISM of VII Zw466 in the HI-dominated regime or implies a large quantity of CO-dark molecular gas, given its high star formation rate. The molecular gas densities and star formation rate densities of VII Zw466 are consistent with the standard Kennicutt-Schmidt star formation law even though we find this galaxy to be H2-deficient. The choice of CO-to-H2 conversion factors cannot explain the apparent H2 deficiency in its entirety. Hence, we find that the collisional ring galaxy, VII Zw466, is either largely deficient in both H2 and HI or contains a large mass of CO-dark gas. A low molecular gas fraction could be due to the enhancement of feedback processes from previous episodes of star formation as a result of the star-forming ISM being confined to the ring. We conclude that collisional ring galaxy formation is an extreme form of galaxy interaction that triggers a strong galactic-wide burst of star formation that may provide immediate negative feedback towards subsequent episodes of star formation---resulting in a short-lived star formation history or, at least, the appearance of a molecular gas deficit.
We present 8.5 arcsec resolution 1.1mm continuum imaging and CO spectroscopic redshift measurements of eight extremely bright submillimetre galaxies identified from the Planck and Herschel surveys, taken with the Large Millimeter Telescopes AzTEC and Redshift Search Receiver instruments. We compiled a candidate list of high redshift galaxies by cross-correlating the Planck Surveyor missions highest frequency channel (857 GHz, FWHM = 4.5 arcmin) with the archival Herschel Spectral and Photometric Imaging Receiver (SPIRE) imaging data, and requiring the presence of a unique, single Herschel counterpart within the 150 arcsec search radius of the Planck source positions with 350 micron flux density larger than 100 mJy, excluding known blazars and foreground galaxies. All eight candidate objects observed are detected in 1.1mm continuum by AzTEC bolometer camera, and at least one CO line is detected in all cases with a spectroscopic redshift between 1.3 < z(CO) < 3.3. Their infrared spectral energy distributions mapped using the Herschel and AzTEC photometry are consistent with cold dust emission with characteristic temperature between $T_d$ = 43 K and 84 K. With apparent infrared luminosity of up to L(IR) = $3times10^{14} mu^{-1} L_odot$, they are some of the most luminous galaxies ever found (with yet unknown gravitational magnification factor $mu$). The analysis of their spectral energy distributions (SEDs) suggests that star formation is powering the bulk of their extremely large IR luminosities. Derived molecular gas masses of $M_{H2}=(0.6-7.8)times 10^{11} M_odot$ (for $mu$~10) also make them some of the most gas-rich high redshift galaxies ever detected.
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