Henrique R. Schmitt

The Navy Precision Optical Interferometer (NPOI) is approaching 30 years of operational life. During that time it has carried out many observations of single and multiple star systems, and has seen upgrades to subsystems and expansion of capabilities. For the last couple of years there has been a major ongoing effort to expand the capabilities of the NPOI with new telescopes, new instruments, and completion of the bootstrapping and imaging capability that was part of the original NPOI design. As part of this upgrade we are also upgrading and replacing some electronic systems. Some technologies which were state-of-the art, e.g. VxWorks, have over the years been overtaken by inexpensive systems such as embedded microcontroller, consumer-grade compact system such as Raspberry Pi¹ and Arduino,² and inexpensive manufacture of simple and powerful custom PCBs. This makes it possible to incorporate remote controls of actuators which will be a major convenience compared to the existing system of manual controls.

We measured the angular diameters of 44 stars with the Navy Precision Optical Interferometer, obtaining uncertainties on the limb-darkened diameter of 2% or less for all but four stars. We then used our diameters with Gaia or Hipparcos parallaxes to calculate each star’s physical radius. We gathered information from the literature to determine bolometric flux and luminosity, and combined that with our diameters to produce an effective temperature. Our sample consists of mostly giant stars, and spans a wide range of spectral classes from B to M.

We explore the properties of ionized gas in the nuclear and circumnuclear environment of the narrow-line Seyfert 1 galaxy NGC 4051 using spectroscopic and imaging observations from the Hubble Space Telescope (HST) and Apache Point Observatory's ARC 3.5 m Telescope. We identify an unresolved moderate-density intermediate-width component and a high-density broad component in the optical emission lines from the active nucleus, as well as spatially resolved emission extending up to ∼1 kpc in the active galactic nucleus (AGN) ionized narrow-line region (NLR) and ∼8 kpc in the stellar ionized host galaxy. The HST narrowband image reveals a distinct conical structure in [O iii] emission toward the NE, and the ionized gas kinematics shows up to two blueshifted velocity components, indicating outflows along the edges of a cone. We introduce an improved model of biconical outflow, with our line of sight passing through the wall of the cone, which suggests that the large number of outflowing UV absorbers seen in NGC 4051 are NLR clouds in absorption. Using the deprojection factors from the biconical geometry, we measure true outflow velocities up to 680 km s⁻¹ at a distance of ∼350 pc; however, we do not find any rotational signature inside a projected distance of ≤ 10″ (∼800 pc) from the nucleus. We compare the gas kinematics with analytical models based on a radiation-gravity formalism, which show that most of the observed NLR outflows are launched within ∼0.5 pc of the nucleus and can travel up to ∼1 kpc from this low-luminosity AGN.

The detection and characterization of supermassive black holes (SMBHs) in local low mass galaxies is crucial to our understanding of the origins of SMBHs. This statement assumes that low mass galaxies have had a relatively quiet cosmic history, so that their black holes have not undergone significant growth and therefore can be treated as relics of the original SMBH seeds. While recent studies have found optical signatures of active galactic nuclei (AGNs) in a growing population of dwarf galaxies, these studies are biased against low metallicity and relatively merger-free galaxies, thus missing precisely the demographic in which to search for the relics of SMBH seeds. Here, we report the detection of the [Si vi]1.963 μm coronal line (CL), a robust indicator of an AGN in the galaxy SDSS J160135.95+311353.7, a nearby (z = 0.031) low metallicity galaxy with a stellar mass approximately an order of magnitude lower than the LMC (M _* ≈ 10^8.56 M _⊙) and no optical evidence for an AGN. The AGN bolometric luminosity implied by the CL detection is ≈10⁴² erg s⁻¹, precisely what is predicted from its near-infrared continuum emission based on well-studied AGNs. Our results are consistent with a black hole of mass ≈10⁵ M _⊙, in line with expectations based on its stellar mass. This is the first time a near-infrared CL has been detected in a low mass, low metallicity galaxy with no optical evidence for AGN activity, providing confirmation of the utility of infrared CLs in finding AGNs in low mass galaxies when optical diagnostics fail. These observations highlight a powerful avenue of investigation to hunt for low mass black holes in the James Webb Space Telescope era.

Outflows of ionized gas driven by active galactic nuclei (AGN) may significantly impact the evolution of their host galaxies. However, determining the energetics of these outflows is difficult with spatially unresolved observations that are subject to strong global selection effects. We present part of an ongoing study using Hubble Space Telescope and Apache Point Observatory spectroscopy and imaging to derive spatially resolved mass outflow rates and energetics for narrow-line region outflows in nearby AGN that are based on multi-component photoionization models to account for spatial variations in gas ionization, density, abundances, and dust content. This expanded analysis adds Mrk 3, Mrk 78, and NGC 1068, doubling our earlier sample. We find that the outflows contain total ionized gas masses of M ≈ 10^5.5–10^7.5 M _⊙ and reach peak velocities of v ≈ 800–2000 km s⁻¹. The outflows reach maximum mass outflow rates of yr⁻¹ and encompass total kinetic energies of E ≈ 10⁵⁴–10⁵⁶ erg. The outflows extend to radial distances of r ≈ 0.1–3 kpc from the nucleus, with the gas masses, outflow energetics, and radial extents positively correlated with AGN luminosity. The outflow rates are consistent with in situ ionization and acceleration where gas is radiatively driven at multiple radii. These radial variations indicate that spatially resolved observations are essential for localizing AGN feedback and determining the most accurate outflow parameters.

We present the first results from the Fundamental Reference active galactic nucleus (AGN) Monitoring Experiment, an observational campaign dedicated to understanding the physical processes that affect the apparent positions and morphologies of AGNs. In this work, we obtained simultaneous Swift X-ray Telescope and Very Long Baseline Array (VLBA) radio observations for a snapshot campaign of 25 local AGNs that form a volume-complete sample with hard X-ray (14–195 keV) luminosities above 10⁴² erg s⁻¹, out to a distance of 40 Mpc. Despite achieving an observation depth of ∼20 μJy, we find that 16 of 25 AGNs in our sample are not detected with the VLBA on milliarcsecond (subparsec) scales, and the corresponding core radio luminosity upper limits are systematically below predictions from the Fundamental Plane of black hole activity. Using archival Jansky Very Large Array (VLA) radio measurements, our sample jumps back onto the Fundamental Plane, suggesting that extended radio emission is responsible for the apparent correlation between radio emission, X-ray emission, and black hole mass. We suggest that this discrepancy is likely due to extranuclear radio emission produced via interactions between the AGN and host environment. We compare VLBA observations of AGNs to VLA observations of nearby Galactic black holes, and we find a mass-independent correlation between radio and X-ray luminosities of black holes of / ∼10⁻⁶, in line with predictions for coronal emission, but allowing for the possibility of truly radio-silent AGNs.

We present optical SuperNova Integral Field Spectrograph integral field spectroscopy, Hubble Space Telescope optical imaging, Chandra X-ray imaging, and Very Large Array radio interferometry of the merging galaxy 2MASX J04234080+0408017, which hosts a Seyfert 2 active galactic nucleus (AGN) at z = 0.046. Our observations reveal that radiatively driven, ionized gas outflows are successful to distances >10 kpc due to the low mass of the host system, encompassing the entirety of the observed optical emission. We also find that at large radii, where observed velocities cannot be reproduced by radiative driving models, high-velocity kinematics are likely due to mechanical driving from AGN winds impacting high-density host material. This impacting deposits sufficient energy to shock the host material, producing thermal X-ray emission and cosmic rays, which in turn promote the formation of in situ radio structure in a pseudo-jet morphology along the high-density lanes.